Infinitivo pessoal: quando flexionar
Infinitivo pessoal: quando flexionar means “Personal infinitive: when to inflect it (own subject) vs leave it bare (after an auxiliary/modal)”. The personal infinitive takes its own endings: eu falar, tu falares, ele falar, nos falarmos, vos falardes, eles falarem. Formation: V-infinitivo + -/-es/-/-mos/-des/-em (sujeito proprio) | auxiliar/modal + infinitivo nu
Personal infinitive: when to inflect it (own subject) vs leave it bare (after an auxiliary/modal)
B2Formation
V-infinitivo + -/-es/-/-mos/-des/-em (sujeito proprio) | auxiliar/modal + infinitivo nu
Explanation
The personal infinitive takes its own endings: eu falar, tu falares, ele falar, nos falarmos, vos falardes, eles falarem. Inflect it when the infinitive has its own subject, different from the main verb: 'E importante voces estudarem' (it's important that YOU study), 'Para nos fazermos isso, precisamos de tempo', 'Depois de eles sairem, apaguem a luz'. You also inflect it for clarity or emphasis, even with the same subject: 'Estudamos muito para passarmos'. Do NOT inflect it when it forms a periphrasis with an auxiliary or modal (poder, dever, querer, ir, comecar a): say 'Eles querem sair', never 'querem sairem'; 'Vamos comer', never 'vamos comermos'. The most common learner mistake is inflecting after a modal: 'podemos irmos' is WRONG, the correct form is 'podemos ir'. Spanish has no personal infinitive at all, so resist translating every 'para que estudemos' as a subjunctive clause when Portuguese can simply say 'para estudarmos'.
Examples
Note
Never inflect the infinitive after an auxiliary or modal verb: 'podemos ir' (not 'podemos irmos'), 'vao viajar' (not 'vao viajarem'). Inflection only kicks in when the infinitive has its own subject.
FAQ
Infinitivo pessoal: quando flexionar — what does it mean and how is it used?
Personal infinitive: when to inflect it (own subject) vs leave it bare (after an auxiliary/modal). The personal infinitive takes its own endings: eu falar, tu falares, ele falar, nos falarmos, vos falardes, eles falarem. Inflect it when the infinitive has its own subject, different from the main verb: 'E importante voces estudarem' (it's important that YOU study), 'Para nos fazermos isso, precisamos de tempo', 'Depois de eles sairem, apaguem a luz'. You also inflect it for clarity or emphasis, even with the same subject: 'Estudamos muito para passarmos'. Do NOT inflect it when it forms a periphrasis with an auxiliary or modal (poder, dever, querer, ir, comecar a): say 'Eles querem sair', never 'querem sairem'; 'Vamos comer', never 'vamos comermos'. The most common learner mistake is inflecting after a modal: 'podemos irmos' is WRONG, the correct form is 'podemos ir'. Spanish has no personal infinitive at all, so resist translating every 'para que estudemos' as a subjunctive clause when Portuguese can simply say 'para estudarmos'.
Infinitivo pessoal: quando flexionar — how do you form it?
V-infinitivo + -/-es/-/-mos/-des/-em (sujeito proprio) | auxiliar/modal + infinitivo nu
Infinitivo pessoal: quando flexionar — any usage notes?
Never inflect the infinitive after an auxiliary or modal verb: 'podemos ir' (not 'podemos irmos'), 'vao viajar' (not 'vao viajarem'). Inflection only kicks in when the infinitive has its own subject.