Most of the Portuguese verbs end in one of the three terminations: -er, -ar or -ir and follow conjugation rules specific to each group of verbs. To conjugate a regular verb in Portuguese, you have to add to the verb root different terminations upon the person, mood, tense. There are also irregular verbs in Portuguese, like "dar", "fazer", "ir", which modify even their root, during conjugation.
Besides the irregular verbs, a Portuguese learner may find it difficult to understand the differences in verbs conjugation between Portugal and Brazil, plus other particularities of the Portuguese verbs:
Depending on the region and register of speech, Portuguese has developed several alternatives for indicating the 3rd person, singular and plural, besides the forms including personal pronouns.
If in most of the languages the infinitive is a one-form mode, in Portuguese, the infinitive can be personal or impersonal. The impersonal infinitive is the base form of the verb, like in any other language. The personal infinitive is often used after prepositions like “ao” or “para” to indicate more clearly to whom the action expressed by the verb refers.
Both verbs mean “to be,” but each of them is used in particular conditions and they are rarely interchangeable. Choosing between “ser” and “estar” can be confusing for learners speaking a mother tongue where there is no such differentiation.
indicates a state, situation or condition which is permanent or unlikely to change in the long-term (like nationality, profession, behavior)
indicates a temporary state, situation or condition (mood, health situation, sensations, location, etc).
The Portuguese language uses many nuances to show the progress of an action or how it occurred and that's why many verbs serve as auxiliaries.
Portuguese auxiliary verbs can be split into 3 categories: