Portuguese conjugation

Portuguese verbs display a high degree of inflection. A typical regular verb has over fifty different forms, expressing up to six different grammatical tenses and three moods. Two forms are peculiar to Portuguese within the Romance languages, shared with Galician:

The personal infinitive, a non-finite form which does not show tense, but is inflected for person and number.
The future subjunctive, is sometimes archaic in some dialects of related languages such as Spanish, but still active in Portuguese.

It has also several verbal periphrases.

Overview

Portuguese verbs have the following properties.

Two numbers—singular, plural
Three persons—first, second, third
Three aspects—perfective, imperfective, progressive*
Two voices—active, passive*
Six morphological forms for tenses, aspects, and/or moods—present, preterite, imperfect, pluperfect, future, and conditional.
Three moods—indicative, subjunctive, imperative

Classes with an asterisk are entirely periphrastic. The passive voice can be constructed in two different ways. The pluperfect and the future of the indicative mood, as well as the conditional form, are often replaced with other verbal constructions or verbal periphrases in the spoken language.

Basic tenses and moods

Conjugation is demonstrated here with the important irregular verb fazer, "to do":
Periphrastic forms are as follows:

Description

The tenses correspond to:

Present : "I do" or "I am doing".
Preterite : "I did" or "I have done".
Imperfect : "I did", "I used to do", "I was doing".
Pluperfect : "I had done".
Future : "I will do", "I am going to do".
Conditional : "I would do". Used in some types of conditional sentences, as a form of courtesy, or as a future-in-the-past.

The five non-finite forms generally correspond to:

infinitive : equivalent to English "to do".
Past participle : equivalent to English "done".
Present participle : Uncommon in modern speech. Somewhat equivalent to English "doer", or used as an adjective relating to an ongoing action, or that action in general. For example, "falante" can mean "talking ", "talkative" or "speaker". See notes above.
Gerund : equivalent to English " doing". Used to actually show/describe ongoing action.
Personal infinitive : " to do", an infinitive which inflects according to its subject; a rare feature that Portuguese shares with Galician.

The moods are used roughly as follows:

Indicative : for factual statements or positive beliefs. Example of an English equivalent: "I have done".
Subjunctive : mostly used when speaking of unreal, uncertain, or unassumed conditions: "Were I to do".
Imperative : for direct commands or requests; equivalent to the English "Do!"

For the Portuguese personal pronouns, see Portuguese [personal pronouns and possessives].

Conjugations

Regular verbs belong to one of three conjugation classes, distinguished by the ending of their infinitive forms :

Those whose infinitive ends in -ar belong to the first conjugation ;
Those whose infinitive ends in -er belong to the second conjugation ;
Those whose infinitive ends in -ir belong to the third conjugation ;

The verb pôr is conventionally placed in the second conjugation by many authors, since it is derived from Old Portuguese poer. In any event, this is an irregular verb whose conjugation must be learned on its own. Other verbs with infinitives ending in -or, such as depor, compor, and propor are derivatives of pôr, and are conjugated in the same way.

Important irregular verbs

The following irregular verbs are used as auxiliary verbs in various periphrastic constructions.

Conditional and future

There are few irregular verbs for these tenses. The indicative future imperfect, conditional, and subjunctive future imperfect are formed by adding to the infinitive of the verb the indicative present inflections of the auxiliary verb haver, the 2nd/3rd conjugation endings of the preterite, imperfect, and the personal infinitive endings, respectively. Thus, for the majority of verbs, the simple personal infinitive coincides with subjunctive future.

Imperative

The affirmative imperative for second person pronouns tu and vós is obtained from the present indicative, by deletion of the final -s. For other persons, and for negative clauses, the present subjunctive takes the role of imperative.

Pronunciation of present inflections

In the present tense, the stress fluctuates between the root and the termination. As a rule of thumb, the last radical vowel will retain its original pronunciation when unstressed and change into,, or – depending on the vowel in question – in case it is stressed. Other vowels and nasalized vowels stay unchanged, as well as the verbs with the diphthongs -ei, -eu, -oi, -ou; they always keep a closed-mid pronunciation; e.g. deixo, endeuso, açoito, roubo, etc. Alternation in stem-stressed forms is blocked when a nasal consonant follows, in which case the higher alternant is used in all forms. For example, in the verb comer, all of the forms como, comes, come, comem have.
Example: Consider the conjugation of correr in the Indicative Present Simple. The first-person singular corro has in the stressed vowel, while other forms corres, corre, correm have.
In Brazil, the following difference applies: Stem-unstressed forms consistently have or for most speakers in most verbs, but there are exceptions, with some dialects likely to present an open form or. At times, the difference is not particularly clear, producing,, particularly in transition zones like the states of Rio de Janeiro, Espírito Santo, Minas Gerais and the Federal District of Brasilia, unless vowel harmony is involved.
This also has repercussions in the imperative and present subjunctive, for their inflections are constructed from the indicative present simple and indicative present simple in the 1st singular person respectively.