Tense–aspect–mood
Tense–aspect–mood or tense–modality–aspect is an important group of grammatical categories, which are marked in different ways by different languages.
TAM covers the expression of three major components of words which lead to or assist in the correct understanding of the speaker's meaning:
- Tense—the position of the state or action in time, that is, whether it is in the past, present or future.
- Aspect—the extension of the state or action in time, that is, whether it is unitary, continuous or repeated.
- Mood or modality—the reality of the state or action, that is, whether it is actual, a possibility or a necessity.
- Tense: He walked, He walks, He will walk.
- Aspect: He walked, He was walking, He used to walk.
- Mood: I can walk, Walk faster!.
In some languages, evidentiality and mirativity may also be included. Therefore, some authors extend this term as "tense–aspect–mood–evidentiality".
Tense-mood-aspect conflation
It is often difficult to untangle these features of a language. Several features may be conveyed by a single grammatical construction. However, this system may not be complete in that not all possible combinations may have an available construction. On the other hand, the same category may be expressed with multiple constructions. In other cases, there may not be delineated categories of tense and mood, or aspect and mood.For instance, many Indo-European languages do not clearly distinguish tense from aspect.
In some languages, such as Spanish and Modern Greek, the imperfective aspect is fused with the past tense in a form traditionally called the imperfect. Other languages with distinct past imperfectives include Latin and Persian.
In the traditional grammatical description of some languages, including English, many Romance languages, and Greek and Latin, "tense" or the equivalent term in that language refers to a set of inflected or periphrastic verb forms that express a combination of tense, aspect, and mood.
In Spanish, the simple conditional is classified as one of the simple tenses, but is named for the mood that it expresses. In Ancient Greek, the perfect tense is a set of forms that express both present tense and perfect aspect, or simply perfect aspect.
However, not all languages conflate tense, aspect and mood. Some analytic languages such as Creole languages have separate grammatical markers for tense, aspect, and/or mood, which comes close to the theoretical distinction.
Creoles
, both Atlantic and non-Atlantic, tend to share a large number of syntactic features, including the avoidance of bound morphemes. Tense, aspect, and mood are usually indicated with separate invariant pre-verbal auxiliaries. Typically the unmarked verb is used for either the timeless habitual or the stative aspect or the past perfective tense–aspect combination. In general creoles tend to put less emphasis on marking tense than on marking aspect. Typically aspectually unmarked stative verbs can be marked with the anterior tense, and non-statives, with or without the anterior marker, can optionally be marked for the progressive, habitual, or completive aspect or for the irrealis mood. In some creoles the anterior can be used to mark the counterfactual. When any of tense, aspect, and modality are specified, they are typically indicated separately with the invariant pre-verbal markers in the sequence anterior relative tense, irrealis mode, non-punctual aspect.Hawaiian Creole English
Hawaiian Creole English, or Hawaiian Pidgin, is a creole language with most of its vocabulary drawn from its superstrate English, but as with all creoles its grammar is very different from that of its superstrate. HCE verbs have only two morphologically distinct forms: the unmarked form and the progressive form with the suffix -in appended to the unmarked form. The past tense is indicated either by the unmarked form or by the preverbal auxiliary wen or bin or haed. However, for "to say" the marked past tense has the obligatory irregular form sed "said", and there are optional irregular past tense forms sin or saw = wen si "saw", keim = wen kam "came", and tol = wen tel "told". The past is indicated only once in a sentence since it is a relative tense.The future marker is the preverbal auxiliary gon or goin "am/is/are going to": gon bai "is going to buy". The future of the past tense/aspect uses the future form since the use of the past tense form to mark the time of perspective retains its influence throughout the rest of the sentence: Da gai sed hi gon fiks mi ap.
There are various preverbal modal auxiliaries: kaen "can", laik "want to", gata "have got to", haeftu "have to", baeta "had better", sapostu "am/is/are supposed to". Tense markers are used infrequently before modals: gon kaen kam "is going to be able to come". Waz "was" can indicate past tense before the future marker gon and the modal sapostu: Ai waz gon lift weits "I was gonna lift weights"; Ai waz sapostu go "I was supposed to go".
There is a preverbal auxiliary yustu for past tense habitual aspect: yustu tink so. The progressive aspect can be marked with the auxiliary ste in place of or in addition to the verbal suffix -in: Wat yu ste it? = Wat yu itin? ; Wi ste mekin da plaen. The latter, double-marked, form tends to imply a transitory nature of the action. Without the suffix, ste can alternatively indicate perfective aspect: Ai ste kuk da stu awredi ; this is true, for instance, after a modal: yu sapostu ste mek da rais awredi. Stat is an auxiliary for inchoative aspect when combined with the verbal suffix -in: gon stat plein. The auxiliary pau without the verbal suffix indicates completion: pau tich "finish teaching". Aspect auxiliaries can co-occur with tense markers: gon ste plei ; wen ste it.
Modern Greek
Modern Greek distinguishes the perfective and imperfective aspects by the use of two different verb stems. For the imperfective aspect, suffixes are used to indicate the past tense indicative mood, the non-past indicative mood, and the subjunctive and imperative moods. For the perfective aspect, suffixes are used to indicate the past tense indicative mood, the subjunctive mood, and the imperative mood. The perfective subjunctive is twice as common as the imperfective subjunctive. The subjunctive mood form is used in dependent clauses and in situations where English would use an infinitive.There is a perfect form in both tenses, which is expressed by an inflected form of the imperfective auxiliary verb έχω "have" and an invariant verb form derived from the perfective stem of the main verb. The perfect form is much rarer than in English. The non-past perfect form is a true perfect aspect as in English.
In addition, all the basic forms can be combined with a particle indicating future tense/conditional mood. Combined with the non-past forms, this expresses an imperfective future and a perfective future. Combined with the imperfective past it is used to indicate the conditional, and with the perfective past to indicate the inferential. If the future particle precedes the present perfect form, a future perfect form results.
Indo-Aryan languages
Hindustani
In Hindustani, grammatical aspects are overtly marked. There are four aspects in Hindustani: Simple Aspect, Habitual Aspect, Perfective Aspect and Progressive Aspect. Periphrastic Hindustani verb forms consist of two elements; the first of these two elements is the aspect marker and the second element is the tense-mood marker. These three aspects are formed from their participle forms being used with the copula verb of Hindustani. However, the aspectual participles can also have the verbs rêhnā, ānā & jānā as their copula which themselves can be conjugated into any of the three grammatical aspects hence forming sub-aspects. Each copula besides honā gives a different nuance to the aspect.The habitual aspect infinitives when formed using the copula rêhnā the following sub-aspectual forms are formed:
The main copula honā in its conjugated form is shown in the table below. These conjugated forms are used to assign a tense and a grammatical mood to the aspectual forms.
Slavic languages
In all Slavic languages, most verbs come in pairs with one member indicating an imperfective aspect and the other indicating a perfective one.Russian
Most Russian verbs come in pairs, one with imperfective aspect and the other with perfective aspect, the latter usually formed from the former with a prefix but occasionally with a stem change or using a different root. Perfective verbs, whether derived or basic, can be made imperfective with a suffix. Each aspect has a past form and a non-past form. The non-past verb forms are conjugated by person/number, while the past verb forms are conjugated by gender/number. The present tense is indicated with the non-past imperfective form. The future in the perfective aspect is expressed by applying the conjugation of the present form to the perfective version of the verb. There is also a compound future imperfective form consisting of the future of "to be" plus the infinitive of the imperfective verb.The conditional mood is expressed by a particle after the past tense form. There are conjugated modal verbs, followed by the infinitive, for obligation, necessity, and possibility/permission.