Latin conjugation

In linguistics and grammar, conjugation has two basic meanings. One meaning is the creation of derived forms of a verb from basic forms, or principal parts.
The second meaning of the word conjugation is a group of verbs which all have the same pattern of inflections. Thus all those Latin verbs which in the present tense have 1st singular -ō, 2nd singular -ās, and infinitive -āre are said to belong to the 1st conjugation, those with 1st singular -eō, 2nd singular -ēs and infinitive -ēre belong to the 2nd conjugation, and so on. The number of conjugations of regular verbs is usually said to be four.
The word "conjugation" comes from the Latin coniugātiō, a calque of the Greek συζυγία, literally "yoking together ".
For examples of verbs and verb groups for each inflectional class, see the Wiktionary appendix pages for first conjugation, second conjugation, third conjugation, and fourth conjugation.

Number of conjugations

The ancient Romans themselves, beginning with Varro, originally divided their verbs into three conjugations, according to whether the ending of the 2nd person singular had an a, an e or an i in it. However, others, such as Sacerdos, Dositheus and Priscian, recognised four different groups.
In modern times grammarians generally recognise four conjugations according to the ending of the active infinitive: namely -āre, -ēre, -ere, or -īre, for example: amō, amāre "to love", videō, vidēre "to see", regō, regere "to rule" and capiō, capere "to capture", audiō, audīre "to hear".
In addition to regular verbs, which belong to one or other of the four regular conjugations, there are also a few irregular verbs, which have a different pattern of endings. The most frequent of these is the verb sum, esse "to be" together with its prefixed derivatives.
There also exist deponent Latin verbs, which though active in meaning have endings identical to the passive endings of ordinary verbs. Examples in the different conjugations are: moror, morārī "to delay", polliceor, pollicērī "to promise", sequor, sequī "to follow" and regredior, regredī "to go back", mentior, mentīrī "to lie ". Some verbs are semi-deponent, using passive forms for the perfect tenses only.

Principal parts

A verb's full paradigm relies on multiple different stems. The present indicative active and the present infinitive are both based on the present stem.
It is not possible to infer the stems for other tenses from the present stem. This means that, although the infinitive active form normally shows the verb conjugation, knowledge of several different forms is necessary to be able to confidently produce the full range of forms for any particular verb.
In a dictionary, Latin verbs are listed with four "principal parts", which allow the student to deduce the other conjugated forms of the verbs. These are:

the first person singular of the present indicative active
the present infinitive active
the first person singular of the perfect indicative active
the supine or, in some grammars, the perfect passive participle, which uses the same stem. Some verbs lack this principal part altogether.

Regular conjugations

First conjugation

The first conjugation is characterized by the vowel ā and can be recognized by the -āre ending of the present active infinitive form. The infectum tenses conjugate as follows :
* The 2nd person singular passive amāberis, amābāris, amēris, amārēris can be shortened to amābere, amābāre, amēre, amārēre. -re was the regular form in early Latin and in Cicero; -ris was preferred later.
In early Latin, the 3rd singular endings -at and -et were pronounced -āt and -ēt with a long vowel.
Other forms:

Infinitive: amāre "to love"
Passive infinitive: amārī "to be loved"
Imperative: amā! "love!"
Future imperative: amātō! "love! "
Indirect imperative: amātō! "let him love!"
Passive imperative: amāre! "be loved!"
Passive future imperative: amātor! "be loved! "
Passive indirect imperative: amātor! "let him be loved!"
Present participle: amāns "loving"
Future participle: amātūrus "going to love"
Gerundive: amandus "needing to be loved"
Gerund: amandī "of loving", amandō "by/for loving", ad amandum "in order to love"

The principal parts usually adhere to one of the following patterns:

The perfect has the suffix -āvī. The majority of first-conjugation verbs follow this pattern, which is considered to be "regular", for example:
* amō, amāre, amāvī, amātum, "to love";
* imperō, imperāre, imperāvī, imperātum, "to order";
* laudō, laudāre, laudāvī, laudātum, "to praise";
* negō, negāre, negāvī, negātum, "to deny";
* nūntiō, nūntiāre, nūntiāvī, nūntiātum, "to announce, report";
* ōrō, ōrāre, ōrāvī, ōrātum, "to beg, pray";
* parō, parāre, parāvī, parātum, "to prepare";
* portō, portāre, portāvī, portātum, "to carry";
* pugnō, pugnāre, pugnāvī, pugnātum, "to fight";
* putō, putāre, putāvī, putātum, "to think";
* rogō, rogāre, rogāvī, rogātum, "to ask";
* servō, servāre, servāvī, servātum, "to save";
* vocō, vocāre, vocāvī, vocātum, "to call";
The perfect has the suffix -uī, for example:
* fricō, fricāre, fricuī, frictum, "to rub";
* secō, secāre, secuī, sectum, "to cut, to divide";
* vetō, vetāre, vetuī, vetitum, "to forbid, to prohibit";
The perfect has the suffix -ī and vowel lengthening in the stem, for example:
* iuvō, iuvāre, iūvī, iūtum, "to help, to assist";
* lavō, lavāre, lāvī, lautum, "to wash, to bathe";
The perfect is reduplicated, for example:
* dō, dare, dedī, datum, "to give"
* stō, stāre, stetī, statum, "to stand";

The verb dō "I give" is irregular in that except in the 2nd singular dās and imperative dā, the a is short, e.g. dabō "I will give".
The a is also short in the supine statum and its derivatives, but the other parts of stō "I stand" are regular.
Deponent verbs in this conjugation all follow the pattern below, which is the passive of the first type above:

Perfect tenses

The three perfectum tenses of the 1st conjugation go as in the following table:
In poetry, the 3rd person plural of the perfect indicative is often amāvēre instead of amāvērunt. Occasionally the form amāverunt is also found.
In early Latin, the future perfect indicative had a short i in amāveris, amāverimus, amāveritis, but by the time of Cicero these forms were usually pronounced with a long i, in the same way as in the perfect subjunctive. Virgil has a short i for both tenses; Horace uses both forms for both tenses; Ovid uses both forms for the future perfect, but a long i in the perfect subjunctive.
The -v- of the perfect active tenses sometimes drops out, especially in the pluperfect subjunctive: amāssem for amāvissem. Forms such as amārat and amāstī are also found.
The passive tenses also have feminine and neuter forms, e.g. amāta est "she was loved", nūntiātum est "it was announced".
Forms made with fuī instead of sum and forem instead of essem are also found, for example amātus fuī, amātus fuerō, amātus forem and so on, but these are not common in classical Latin. See Latin tenses.
For other meanings of the perfect and pluperfect subjunctive, see Latin tenses#Jussive subjunctive.
Other forms:

Perfect infinitive active: amāvisse "to have loved"
Perfect infinitive passive: amātus esse "to have been loved"
Perfect participle passive: amātus, -a, -um "loved "

Second conjugation

The second conjugation is characterized by the vowel ē, and can be recognized by the -eō ending of the first person present indicative and the -ēre ending of the present active infinitive form:
The passive videor also often means "I seem".
Other forms:

Infinitive: vidēre "to see"
Passive infinitive: vidērī "to be seen"
Imperative: vidē! "see!"
Future imperative: vidētō! "see! "
Passive imperative: vidēre! "be seen!"
Present participle: vidēns "seeing"
Future participle: vīsūrus "going to see"
Gerundive: videndus "needing to be seen"
Gerund: videndī "of seeing", videndō "by /for seeing", ad videndum "in order to see"

The principal parts usually adhere to one of the following patterns:

The perfect has the suffix -uī. Verbs which follow this pattern are considered to be "regular". Examples:
* dēbeō, dēbēre, dēbuī, dēbitum "to owe, be obliged"
* doceō, docēre, docuī, doctum "to teach, to instruct"
* iaceō, iacēre, iacuī, iacitum "to lie "
* mereō, merēre, meruī, meritum "to deserve"
* misceō, miscēre, miscuī, mixtum "to mix"
* moneō, monēre, monuī, monitum "to warn, advise"
* noceō, nocēre, nocuī, nocitum "to be harmful"
* praebeō, praebēre, praebuī, praebitum "to provide, show"
* teneō, tenēre, tenuī, tentum "to hold, to keep"
* terreō, terrēre, terruī, territum "to frighten, to deter"
* timeō, timēre, timuī, – "to fear"
* valeō, valēre, valuī, "to be strong"
The perfect has the suffix –ēvī. Example:
* dēleō, dēlēre, dēlēvī, dēlētum "to destroy"
* fleō, flēre, flēvī, flētum "to weep"

In verbs with perfect in -vī, syncopated forms are common, such as dēlēram, dēlēssem, dēlēstī for dēlēveram, dēlēvissem, dēlēvistī.

The perfect has the suffix –īvī. Example:
* cieō, ciēre, cīvī, citum "to arouse, to stir"
The perfect has the suffix -sī. Examples:
* ārdeō, ārdēre, ārsī, ārsum "to burn"
* augeō, augēre, auxī, auctum "to increase, to enlarge"
* haereō, haerēre, haesī, haesum "to stick, to adhere, to get stuck"
* iubeō, iubēre, iussī, iussum "to order"
* maneō, manēre, mānsī, mānsum "to remain"
* persuādeō, persuādēre, persuāsī, persuāsum "to persuade"
* rīdeō, rīdēre, rīsī, rīsum "to laugh"
The perfect is reduplicated with -ī. Examples:
* mordeō, mordēre, momordī, morsum "to bite"
* spondeō, spondēre, spopondī, spōnsum "to vow, to promise"
The perfect has suffix -ī and vowel lengthening in the stem. Examples:
* caveō, cavēre, cāvī, cautum "to be cautious"
* faveō, favēre, fāvī, fautum "to favour"
* foveō, fovēre, fōvī, fōtum "to caress, to cherish"
* sedeō, sedēre, sēdī, sessum "to sit"
* videō, vidēre, vīdī, vīsum "to see"
The perfect has suffix -ī. Examples:
* respondeō, respondēre, respondī, respōnsum "to reply"
* strīdeō, strīdēre, strīdī, – "to hiss, to creak"

Deponent verbs in this conjugation are few. They mostly go like the passive of terreō, but fateor and confiteor have a perfect participle with ss:
The following are semi-deponent, that is, they are deponent only in the three perfect tenses:

Third conjugation

The third conjugation has a variable short stem vowel, which may be e, i, or u in different environments. Verbs of this conjugation end in -ere in the present active infinitive. Deponent verbs have the infinitive -ī.
The future tense in the 3rd and 4th conjugation differs from that in the 1st and 2nd conjugation.
Other forms:

Infinitive: dūcere "to lead"
Passive infinitive: dūcī "to be led"
Imperative: dūc! "lead!"
Future imperative: dūcitō! "lead! "
Passive imperative: dūcere! "be led!"
Present participle: dūcēns "leading"
Future participle: ductūrus "going to lead"
Gerundive: dūcendus "needing to be led"
Gerund: dūcendī "of leading", dūcendō "by /for leading", ad dūcendum "in order to lead"

Four 3rd conjugation verbs usually have no ending in the imperative singular: dūc! "lead!", dīc! "say!", fer! "bring!", fac! "do!".
Others, like curre "run!", have the ending -e.
There is no regular rule for constructing the perfect stem of third-conjugation verbs, but the following patterns are used:

The perfect has suffix -sī. Examples:
* carpō, carpere, carpsī, carptum "to pluck, to select"
* cēdō, cēdere, cessī, cessum "to yield, depart"
* claudō, claudere, clausī, clausum "to close"
* contemnō, contemnere, contempsī, contemptum "to despise, disdain, treat with contempt"
* dīcō, dīcere, dīxī, dictum "to say"
* dīvidō, dīvidere, dīvīsī, dīvīsum "to divide"
* dūcō, dūcere, dūxī, ductum "to lead"
* flectō, flectere, flexī, flexum "to bend, to twist"
* gerō, gerere, gessī, gestum "to wear, to bear; wage "
* mittō, mittere, mīsī, missum "to send"
* regō, regere, rēxī, rēctum "to rule"
* scrībō, scrībere, scrīpsī, scrīptum "to write"
* tegō, tegere, tēxī, tēctum "to cover, conceal"
* trahō, trahere, trāxī, trāctum "to drag, to pull"
* vīvō, vīvere, vīxī, vīctum "to live"
The perfect is reduplicated with suffix –ī. Examples:
* cadō, cadere, cecidī, cāsum "to fall"
* caedō, caedere, cecīdī, caesum "to kill, to slay"
* currō, currere, cucurrī, cursum "to run, to race"
* discō, discere, didicī, – "to learn"
* fallō, fallere, fefellī, falsum "to cheat"
* pēdō, pēdere, pepēdī, pēditum "to fart"
* pellō, pellere, pepulī, pulsum "to beat, to drive away"
* pōscō, pōscere, popōscī, – "to claim, request"
* tangō, tangere, tetigī, tāctum "to touch, to hit"
* tendō, tendere, tetendī, tentum/tēnsum "to stretch"

Although dō, dare, dedī, datum "to give" is 1st conjugation, its compounds are 3rd conjugation and have internal reduplication:
Likewise the compounds of sistō have internal reduplication. Although sistō is transitive, its compounds are intransitive:

The perfect has suffix -vī. Examples:
* linō, linere, lēvī, litum "to smear, to daub"
* petō, petere, petīvī, petītum "to seek, to attack"
* quaerō, quaerere, quaesīvī, quaesītum "to look for, ask"
* serō, serere, sēvī, satum "to sow, to plant"
* sternō, sternere, strāvī, strātum "to spread, to stretch out"
* terō, terere, trīvī, trītum "to rub, to wear out"
The perfect has suffix -ī and vowel lengthening in the stem. If the present stem has an n infix, as in fundō, relinquō and vincō, the infix disappears in the perfect. In some cases, the long vowel in the perfect is thought to be derived from an earlier reduplicated form, e.g. *e-agī > ēgī, *e-emī > ēmī. Examples:
* agō, agere, ēgī, āctum "to do, to drive"
* cōgō, cōgere, coēgī, coāctum "to compel, gather together"
* emō, emere, ēmī, ēmptum "to buy"
* fundō, fundere, fūdī, fūsum "to pour"
* legō, legere, lēgī, lēctum "to collect, to read"
* relinquō, relinquere, relīquī, relictum "to leave behind"
* rumpō, rumpere, rūpī, ruptum "to burst"
* vincō, vincere, vīcī, victum "to conquer, to defeat"
The perfect has suffix -ī only. Examples:
* ascendō, ascendere, ascendī, ascēnsum "to climb, to go up"
* cōnstituō, cōnstituere, cōnstituī, cōnstitūtum "to establish, decide, cause to stand"
* dēfendō, dēfendere, dēfendī, dēfēnsum "to defend"
* expellō, expellere, expulī, expulsum "to drive out, expel"
* īcō, īcere, īcī, ictum "to strike"
* metuō, metuere, metuī, metūtum "to fear, be apprehensive"
* occīdō, occīdere, occīdī, occīsum "to kill"
* ostendō, ostendere, ostendī, ostentum "to show"
* tollō, tollere, sustulī, sublātum "to lift, raise, remove"
* vertō, vertere, vertī, versum "to turn"
* vīsō, vīsere, vīsī, vīsum "to visit"
The perfect has suffix –uī. Examples:
* colō, colere, coluī, cultum "to cultivate, to till"
* cōnsulō, cōnsulere, cōnsuluī, cōnsultum "to consult, act in the interests of"
* gignō, gignere, genuī, genitum "to beget, to cause"
* molō, molere, moluī, molitum "to grind"
* pōnō, pōnere, posuī, positum "to place"
* texō, texere, texuī, textum "to weave, to plait"
* vomō, vomere, vomuī, vomitum "to vomit"
The present tense indicative first person singular form has suffix –scō. Examples:
* adolēscō, adolēscere, adolēvī, adultum "to grow up, to mature"
* nōscō, nōscere, nōvī, nōtum "to get to know, to learn"
* pāscō, pāscere, pāvī, pāstum "to feed upon, to feed "
* quiēscō, quiēscere, quiēvī, quiētum "to rest, keep quiet"

Deponent verbs in the 3rd conjugation include the following:
There are also a number of 3rd conjugation deponents with the ending -scor:
Deponent in some tenses only is the following:
The following is deponent only in the infectum tenses:

Third conjugation -iō verbs

Intermediate between the third and fourth conjugation are the third-conjugation verbs with suffix –iō. These resemble the fourth conjugation in some forms.
Other forms:

Infinitive: capere "to capture, to take"
Passive infinitive: capī "to be captured"
Imperative: cape! "capture!"
Future imperative: capitō! "capture! "
Passive imperative: capere! "be captured!"
Future passive imperative: capitor! "be captured! "
Present participle: capiēns "capturing"
Future participle: captūrus "going to capture"
Gerundive: capiendus "needing to be captured"
Gerund: capiendī "of capturing", capiendō "by /for capturing", ad capiendum "in order to capture"

Some examples are:
Deponent verbs in this group include:

Fourth conjugation

The fourth conjugation is characterized by the vowel ī and can be recognized by the -īre ending of the present active infinitive. Deponent verbs have the infinitive -īrī:
Other forms:

Infinitive: audīre "to hear"
Passive infinitive: audīrī "to be heard"
Imperative: audī! "hear!"
Future imperative: audītō! "hear! "
Passive imperative: audīre! "be heard!"
Present participle: audiēns "hearing"
Future participle: audītūrus "going to hear"
Gerundive: audiendus "needing to be heard"
Gerund: audiendī "of hearing", audiendō "by /for hearing", ad audiendum "in order to hear"

Principal parts of verbs in the fourth conjugation generally adhere to the following patterns:

The perfect has suffix -vī. Verbs which adhere to this pattern are considered to be "regular". Examples:
* audiō, audīre, audīvī, audītum "to hear, listen "
* custōdiō, custōdīre, custōdīvī, custōdītum "to guard"
* dormiō, dormīre, dormīvī, dormītum "to sleep"
* impediō, impedīre, impedīvī, impedītum "to hinder, impede"
* mūniō, mūnīre, mūnīvī, mūnītum "to fortify, to build"
* pūniō, pūnīre, pūnīvī, pūnītum "to punish"
* sciō, scīre, scīvī, scītum "to know"
The perfect has suffix -uī. Examples:
* aperiō, aperīre, aperuī, apertum "to open, to uncover"
The perfect has suffix -sī. Examples:
* saepiō, saepīre, saepsī, saeptum "to surround, to enclose"
* sanciō, sancīre, sānxī, sānctum "to confirm, to ratify"
* sentiō, sentīre, sēnsī, sēnsum "to feel, to perceive"
* vinciō, vincīre, vīnxī, vīnctum "to bind"
The perfect has suffix -ī and reduplication. Examples:
* reperiō, reperīre, repperī, repertum "to find, discover"
The perfect has suffix -ī and vowel lengthening in the stem. Examples:
* veniō, venīre, vēnī, ventum "to come, to arrive"
* inveniō, invenīre, invēnī, inventum "to find"

Deponent verbs in the 4th conjugation include the following:
The verb orior, orīrī, ortus sum "to arise" is also regarded as 4th conjugation, although some parts, such as the 3rd singular present tense oritur and imperfect subjunctive orerer, have a short vowel like the 3rd conjugation. But its compound adorior "to rise up, attack" is entirely 4th conjugation.
In the perfect tenses, shortened forms without -v- are common, for example, audīstī, audiērunt, audierat, audīsset for audīvistī, audīvērunt, audīverat, audīvisset. Cicero, however, prefers the full forms audīvī, audīvit to audiī, audiit.

Irregular verbs

''Sum'' and ''possum''

The verb sum, esse, fuī "to be" is the most common verb in Latin. It is conjugated as follows:
In early Latin, siem, siēs, siet can be found for the present subjunctive sim, sīs, sit. In poetry the subjunctive fuam, fuās, fuat also sometimes occurs.
An alternative imperfect subjunctive is sometimes made using forem, forēs, foret etc. See further: Latin tenses#Foret.
Other forms:

Infinitive: esse "to be", posse "to be able"
Perfect infinitive: fuisse "to have been", potuisse "to have been able"
Future infinitive: fore "to be going to be"
Imperative: es! "be!"
Future imperative: estō! "be! "
Future participle: futūrus "going to be"

The present participle is found only in the compounds absēns "absent" and praesēns "present".
In Plautus and Lucretius, an infinitive potesse is sometimes found for posse "to be able".
The principal parts of these verbs are as follows:
The perfect tenses conjugate in the regular way.
For the difference in meaning between eram and fuī, see Latin tenses#Difference between eram and fuī

''Volō'', ''nōlō'', and ''mālō''

The verb volō and its derivatives nōlō and mālō resemble a 3rd conjugation verb, but the present subjunctive ending in -im is different:
The spellings volt and voltis were used up until the time of Cicero for vult and vultis.
These verbs are not used in the passive.
Other forms:

Infinitive: velle "to want", nōlle "to be unwilling", mālle "to prefer"
Present participle: volēns "willing", nōlēns "unwilling"
Imperative: nōlī, pl. nōlīte

Principal parts:
The perfect tenses are formed regularly.

''Eō'' and compounds

The verb eō "I go" is an irregular 4th conjugation verb, in which the i of the stem sometimes becomes e. Like 1st and 2nd conjugation verbs, it uses the future -bō, -bis, -bit:
Other forms:

Infinitive: īre "to go"
Passive infinitive: īrī "to go"
Imperative: ī! "go!"
Future imperative: ītō! "go! "
Present participle: iēns "going"
Future participle: itūrus "going to go"
Gerundive: eundum "necessary to go"
Gerund: eundī "of going", eundō "by / for going", ad eundum "in order to go"

The impersonal passive forms ītur "they go", itum est "they went" are sometimes found.
The principal parts of some verbs which conjugate like eō are the following:
In the perfect tenses of these verbs, the -v- is almost always omitted, especially in the compounds, although the form exīvit is common in the Vulgate Bible translation.
In some perfect forms, the vowels ii- are contracted to ī-: second person singular perfect īstī, second person plural perfect īstis; pluperfect subjunctive īssem, īssēs,..., īssent; perfect infinitive īsse.
The verb queō, quīre, quiī/quīvī, quitum "to be able" has forms similar to eō.

''Ferō'' and compounds

The verb ferō, ferre, tulī, lātum "to bring, to bear, to carry" is 3rd conjugation, but irregular in that the vowel following the root fer- is sometimes omitted. The perfect tense tulī and supine stem lātum are also irregularly formed.
The future tense in the 3rd and 4th conjugation differs from that in the 1st and 2nd conjugation.
Other forms:

Infinitive: ferre "to bring"
Passive infinitive: ferrī "to be brought"
Imperative: fer! "bring!"
Passive imperative: ferre! "be carried!"
Present participle: ferēns "bringing"
Future participle: lātūrus "going to bring"
Gerundive: ferendus "needing to be brought"
Gerund: ferendī "of bringing", ferendō "by /for bringing", ad ferendum "in order to bring"

Compounds of ferō include the following:
The principal parts of some verbs which conjugate like ferō are the following:
The perfect tense sustulī, however, belongs to the verb tollō:

''Fīō''

The irregular verb fīō, fierī, factus sum "to become, to happen, to be done, to be made" as well as being a verb in its own right serves as the passive of faciō, facere, fēcī, factum "to do, to make". The perfect tenses are identical with the perfect passive tenses of faciō.
The 1st and 2nd plural forms are almost never found.
Other forms:

Infinitive: fierī "to become, to be done, to happen"
Imperative: fī! "become!"

''Edō''

The verb edō, edere/ēsse, ēdī, ēsum "to eat" has regular 3rd conjugation forms appearing alongside irregular ones:
Other forms:

Infinitive: edere/ēsse "to eat"
Passive infinitive: edī "to be eaten"
Imperative: ede!/ēs! "eat!"
Present participle: edēns "eating"
Future participle: ēsūrus "going to eat"
Gerundive: edendus "needing to be eaten"
Gerund: edendī "of eating", edendō "by /for eating", ad edendum "in order to eat" / "for eating"

The passive form ēstur "it is eaten" is also found.
The present subjunctive edim, edīs, edit etc. is found mostly in early Latin.
In writing, there is a possibility of confusion between the forms of this verb and those of sum "I am" and ēdō "I give out, put forth"; for example, ēsse "to eat" vs. esse "to be"; edit "he eats" vs. ēdit "he gives out".
The compound verb comedō, comedere/comēsse, comēdī, comēsum "to eat up, consume" is similar.

Non-finite forms

The non-finite forms of verbs are participles, infinitives, supines, gerunds and gerundives. The verbs used are:

Participles

There are four participles: present active, perfect passive, future active, and future passive.

The present active participle is declined as a 3rd declension adjective. The ablative singular is -e, but the plural follows the i-stem declension with genitive -ium and neuter plural -ia.
The perfect passive participle is declined like a 1st and 2nd declension adjective.
*In all conjugations, the perfect participle is formed by removing the –um from the supine, and adding a –us.
The future active participle is declined like a 1st and 2nd declension adjective.
*In all conjugations the -um is removed from the supine, and an -ūrus is added.
The future passive participle, more usually called the gerundive, is formed by taking the present stem, adding "-nd-", and the usual first and second declension endings. Thus laudare forms laudandus. The usual meaning is "needing to be praised", expressing a sense of obligation.

Infinitives

There are seven main infinitives. They are in the present active, present passive, perfect active, perfect passive, future active, future passive, and potential active. Further infinitives can be made using the gerundive.

The present active infinitive is the second principal part. It plays an important role in the syntactic construction of Accusative and infinitive, for instance.
*laudāre means, "to praise."
The present passive infinitive is formed by adding a –rī to the present stem. This is only so for the first, second and fourth conjugations. In the third conjugation, the thematical vowel, e, is taken from the present stem, and an –ī is added.
*laudārī translates as "to be praised."
The perfect active infinitive is formed by adding an –isse onto the perfect stem.
*laudāvisse/laudāsse translates as "to have praised."
The perfect passive infinitive uses the perfect passive participle along with the auxiliary verb esse. The perfect passive infinitive must agree with what it is describing in number, gender, and case.
*laudātus esse means, "to have been praised."
The future active infinitive uses the future active participle with the auxiliary verb esse.
*laudātūrus esse means, "to be going to praise." The future active infinitive must agree with what it is describing in number, gender, and case.
*Esse has two future infinitives: futurus esse and fore
The future passive infinitive uses the supine with the auxiliary verb īrī. Because the first part is a supine, the ending -um does not change for gender or number.
*laudātum īrī is translated as "to be going to be praised." This is normally used in indirect speech. For example: Spērat sē absolūtum īrī. "He hopes that he will be acquitted."
The potential infinitive uses the future active participle with the auxiliary verb fuisse.
*laudātūrus fuisse is used only in indirect statements to represent a potential imperfect or pluperfect subjunctive of direct speech. It is translated with "would" or "would have". For example: nōn vidētur mentītūrus fuisse, nisī dēspērāsset 'it seems unlikely that he would have told a lie, if he had not been desperate'

	laudāre	terrēre	petere	capere	audīre
Present active	laudāre	terrēre	petere	capere	audīre
Present passive	laudārī	terrērī	petī	capī	audīrī
Perfect active	laudāvisse	terruisse	petīvisse	cēpisse	audīvisse
Perfect passive	laudātus esse	territus esse	petītus esse	captus esse	audītus esse
Future active	laudātūrus esse	territūrus esse	petītūrus esse	captūrus esse	audītūrus esse
Future passive	laudātum īrī	territum īrī	petītum īrī	captum īrī	audītum īrī
Potential	laudātūrus fuisse	territūrus fuisse	petītūrus fuisse	captūrus fuisse	audītūrus fuisse

The future passive infinitive was not very commonly used. The Romans themselves often used an alternate expression, fore ut followed by a subjunctive clause.

Supine

The supine is the fourth principal part of the verb, as given in Latin dictionaries. It resembles a masculine noun of the fourth declension. Supines only occur in the accusative and ablative cases.

The accusative form ends in a –um, and is used with a verb of motion in order to show purpose. Thus it is only used with verbs like īre "to go", venīre "to come", etc. The accusative form of a supine can also take an object if needed.
*Pater līberōs suōs laudātum vēnit. – The father came to praise his children.
The ablative, which ends in a –ū, is used with the Ablative of Specification.
*Arma haec facillima laudātū erant. – These arms were the easiest to praise.

Gerund

The gerund is formed similarly to the present active participle. However, the -ns becomes an -ndus, and the preceding ā or ē is shortened. Gerunds are neuter nouns of the second declension, but the nominative case is not present. The gerund is a noun, meaning "the act of doing ", and forms a suppletive paradigm to the infinitive, which cannot be declined. For example, the genitive form laudandī can mean "of praising", the dative form laudandō can mean "for praising", the accusative form laudandum can mean "praising", and the ablative form laudandō can mean "by praising", "in respect to praising", etc.
One common use of the gerund is with the preposition ad to indicate purpose. For example, paratus ad oppugnandum could be translated as "ready to attack". However the gerund was avoided when an object was introduced, and a passive construction with the gerundive was preferred. For example, for "ready to attack the enemy" the construction paratus ad hostes oppugnandos is preferred over paratus ad hostes oppugnandum.

Gerundive

The gerundive has a form similar to that of the gerund, but it is a first and second declension adjective, and functions as a future passive participle. It means " to be...ed". Often, the gerundive is used with part of the verb esse, to show obligation.

Puer laudandus est "The boy needs to be praised"
Oratio laudanda est means "The speech is to be praised". In such constructions a substantive in dative may be used to identify the agent of the obligation, as in Oratio nobis laudanda est meaning "The speech is to be praised by us" or "We must praise the speech".

An older form of the 3rd and 4th conjugation gerundive ends in -undum, e.g.. This ending is also found with the gerundive of eō 'I go': eundum est 'it is necessary to go'.
For some examples of uses of Latin gerundives, see the Gerundive article.

Periphrastic conjugations

There are two periphrastic conjugations. One is active, and the other is passive.

Active

The first periphrastic conjugation uses the future participle. It is combined with the forms of esse. It is translated as "I am going to praise", "I was going to praise", etc.

	Conjugation	Translation
Pres. ind.	laudātūrus sum	I am going to praise
Imp. ind.	laudātūrus eram	I was going to praise
Fut. ind.	laudātūrus erō	I shall be going to praise
Perf. ind.	laudātūrus fuī	I have been going to praise
Plup. ind.	laudātūrus fueram	I had been going to praise
Fut. perf. ind.	laudātūrus fuerō	I shall have been going to praise
Pres. subj.	laudātūrus sim	I may be going to praise
Imp. subj.	laudātūrus essem	I should be going to praise
Perf. subj.	laudātūrus fuerim	I may have been going to praise
Plup. subj.	laudātūrus fuissem	I should have been going to praise

Passive

The second periphrastic conjugation uses the gerundive. It is combined with the forms of esse and expresses necessity. It is translated as "I am needing to be praised", "I was needing to be praised", etc., or as "I have to be praised", "I had to be praised", etc. It may also be translated in English word by word, as in "You are to be praised."

	Conjugation	Translation
Pres. ind.	laudandus sum	I am needing to be praised
Imp. ind.	laudandus eram	I was needing to be praised
Fut. ind.	laudandus erō	I will be needing to be praised
Perf. ind.	laudandus fuī	I was needing to be praised
Plup. ind.	laudandus fueram	I had been needing to be praised
Fut. perf. ind.	laudandus fuerō	I will have been needing to be praised
Pres. subj.	laudandus sim	I may be needing to be praised
Imp. subj.	laudandus essem	I should be needing to be praised
Perf. subj.	laudandus fuerim	I may have been needing to be praised
Plup. subj.	laudandus fuissem	I should have been needing to be praised
Pres. inf.	laudandus esse	To be needing to be praised
Perf. inf.	laudandus fuisse	To have been needing to be praised

Peculiarities

Deponent and semi-deponent verbs

s are verbs that are passive in form but active in meaning. These verbs have only three principal parts, since the perfect of ordinary passives is formed periphrastically with the perfect participle, which is formed on the same stem as the supine. Some examples coming from all conjugations are:
Deponent verbs use active conjugations for tenses that do not exist in the passive: the gerund, the supine, the present and future participles and the future infinitive. They cannot be used in the passive themselves, and their analogues with "active" form do not in fact exist: one cannot directly translate "The word is said" with any form of loquī, and there are no forms like loquō, loquis, loquit, etc.
Semi-deponent verbs form their imperfective aspect tenses in the manner of ordinary active verbs; but their perfect tenses are built periphrastically like deponents and ordinary passives; thus, semi-deponent verbs have a perfect active participle instead of a perfect passive participle. An example:
Unlike the proper passive of active verbs, which is always intransitive, some deponent verbs are transitive, which means that they can take an object. For example:
Note: In the Romance languages, which lack deponent or passive verb forms, the Classical Latin deponent verbs either disappeared or changed to a non-deponent form. For example, in Spanish and Italian, mīrārī changed to mirar by changing all the verb forms to the previously nonexistent "active form", and audeō changed to osar by taking the participle ausus and making an -ar verb out of it.

Defective verbs

are verbs that are conjugated in only some instances.

Some verbs are conjugated only in the perfective aspect's tenses, yet have the imperfective aspect's tenses' meanings. As such, the perfect becomes the present, the pluperfect becomes the imperfect, and the future perfect becomes the future. Therefore, the defective verb ōdī means "I hate." These defective verbs' principal parts are given in vocabulary with the indicative perfect in the first person and the perfect active infinitive. Some examples are:
A few verbs, the meanings of which usually have to do with speech, appear only in certain occurrences.

The following are conjugated irregularly:

''For''

The Romance languages lost many of these verbs, but others survived but became regular fully conjugated verbs.

Impersonal verbs

Impersonal verbs are those lacking a person. In English impersonal verbs are usually used with the neuter pronoun "it". Latin uses the third person singular. These verbs lack a fourth principal part. A few examples are:

Irregular future active participles

The future active participle is normally formed by removing the –um from the supine, and adding a –ūrus. However, some deviations occur.

Present active infinitive	Supine	Future active participle	Meaning
iuvāre	iūtum	iuvātūrus	going to help
lavāre/lavere	lavātum	lavātūrus	going to wash
parere	partum	paritūrus	going to produce
ruere	rutum	ruitūrus	going to fall
secāre	sectum	secātūrus	going to cut
fruī	frūctum/fruitum	fruitūrus	going to enjoy
nāscī	nātum	nātūrus/nascitūrus	going to be born
morī	mortuum	moritūrus	going to die
orīrī	ortum	oritūrus	going to rise

Alternative verb forms

Several verb forms may occur in alternative forms :

The ending –ris in the passive voice may be –re as in:
The ending –ērunt in the perfect may be –ēre as in:
The ending –ī in the passive infinitive may be –ier as in:

Syncopated verb forms

Like in most Romance languages, syncopated forms and contractions are present in Latin. They may occur in the following instances:

Perfect stems that end in a –v may be contracted when inflected.
The compounds of nōscere and movēre can also be contracted.