Non-finite verb forms

The non-finite verb forms (Portuguese formas nominais do verbo) are the three forms that do not in themselves express person, number, mood or tense: the infinitive, the gerund and the participle. The Portuguese name — “nominal forms” — reflects the fact that they share properties with nouns: the infinitive often behaves like a noun, the participle like an adjective, the gerund like an adverb. By contrast, the forms that mark person (amo “I love”, amavas “you loved”, amaríamos “we would love”) are called finite.

All three have fixed endings, regular in most verbs:

The infinitive

The infinitive is the citation form of the verb — the form under which it appears in dictionaries — and always ends in -r: falar “to speak”, vender “to sell”, sentir “to feel”. It names the verbal process in its most general form and can stand in the position of a noun: errar é humano “to err is human”, o cantar das aves “the singing of the birds”.

Portuguese distinguishes two kinds of infinitive. The impersonal infinitive is invariable (é bom estudar “it is good to study”). The personal or inflected infinitive — a rarity among the Romance languages — takes person endings when it has a subject of its own: é bom estudares “it is good for you to study”, para chegarmos a horas “so that we arrive on time”. So characteristic is this device that it has an article of its own.

The gerund

The gerund ends in -ndo and expresses an ongoing process or a circumstance accompanying the main action. Its value is chiefly adverbial:

In European Portuguese the gerund remains alive in these adverbial uses and in reduced clauses, but it has retreated in its progressive value — that of marking an action in progress at the moment of speaking. That value is normally expressed by a periphrasis, as we shall see.

The participle

In its regular form the participle ends in -do and has two main jobs. With the auxiliaries ter and haver it builds the compound tenses, and there it is invariable: tinha falado “I had spoken”, havíamos partido “we had left”. With ser or estar, or used adjectivally, it agrees in gender and number with the noun: as cartas foram escritas “the letters were written”, a porta está fechada “the door is closed”.

Double participles

Many verbs have two participles: a regular one, in -ado / -ido, and an irregular, shorter one. The traditional norm reserves the regular form for the compound tenses (with ter / haver) and the short form for the passive and adjectival use (with ser / estar), though actual usage is less rigid.

Infinitive	Regular (ter/haver)	Short (ser/estar)
*aceitar* (accept)	aceitado	aceite
*entregar* (deliver)	entregado	entregue
*ganhar* (win)	ganhado	ganho
*pagar* (pay)	pagado	pago
*limpar* (clean)	limpado	limpo
*matar* (kill)	matado	morto

In European Portuguese, short forms such as aceite, ganho, gasto and pago now prevail even with ter and haver (tinha aceite, tinha pago), while the regular form feels increasingly archaic.

”Estar a + infinitive” versus the gerund

The best-known syntactic hallmark of European Portuguese in this area is the construction of progressive aspect. To say that an action is in progress, the European standard uses estar a + infinitive:

The same pattern extends to other aspectual auxiliaries: andar a, continuar a, começar a (ando a estudar alemão “I’m studying German”, continua a chover “it keeps raining”). The progressive gerund (estou lendo), though grammatical and historically legitimate, today sounds regional or literary in Portugal.

In short

The non-finite forms are the unconjugated skeleton of the verb: the infinitive names the process, the gerund presents it as ongoing or as a circumstance, and the participle makes it agree with a noun or build the compound tenses. Within this set, the choice between estar a + infinitive and the gerund is the point at which European syntax most visibly parts company with Brazilian.