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:
Conjugation is demonstrated here with the important irregular verb "to do". The Portuguese names of the tenses and moods are given along with their English translations. The periphrastic forms are as follows :
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 Portuguesepoer. 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.
The following irregular verbs are used as auxiliary verbs in various periphrastic constructions.
''ter'' – to have
''estar'' – to be
''ser'' – to be
''haver'' – to have, to happen, there to be
''pôr'' - to put
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 verbhaver, 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 Brazilian Federal District, 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.
Verbs ''pelar'', ''amar'' and ''rendar''
Verbs ''correr'', ''comer'', ''romper'' and ''absorver''
