Verb + infinitive: querer, poder, precisar, saber, dever, conseguir

What it is

Many everyday sentences are built from two verbs: a conjugated verb that says what you want, can, need, know how to, should or manage to do, followed by an infinitive for the action itself: Quero aprender português (I want to learn Portuguese). With six verbs (querer, poder, precisar, saber, dever and conseguir) and the infinitives you already know, you can make requests, ask permission and talk about plans from your first week.

How to form it

• Only the first verb changes: eu quero viajar, eles querem viajar. The infinitive never does.
• Nothing goes between the two verbs: no “to”, no para, no a. Quero viajar.
• não goes before the conjugated verb: Não posso sair hoje.
• precisar takes de before a noun or a pronoun (Preciso de ajuda. Preciso de você.), but in Brazil not before an infinitive: Preciso sair.
• Watch the irregular forms: posso, quer (no final -e), sei and consigo. In conseguir the eu form changes e to i, and the u in consegue keeps the g hard.

When to use it

• Quero conhecer o Pantanal.I want to visit the Pantanal.querer: a wish
• Posso entrar?May I come in?poder: permission
• Você pode repetir, por favor?Could you repeat that, please?poder: a request
• Preciso trabalhar amanhã.I need to work tomorrow.precisar: a need
• Sei dirigir.I can drive (I know how).saber: a skill
• Não consigo abrir a porta.I can’t get the door open.conseguir: managing, or not
• Você deve descansar.You should rest.dever: advice
• Deve ser caro.It must be expensive.dever: a guess

Several of these verbs also work as short answers and set phrases: Posso? — Pode! (May I? — Go ahead!), Pode ser (Sounds good, or Maybe), Não precisa (No need), Quer? (Want some?).

Contrasts and traps

• English can has three translations. saber is a skill you have learned: Sei nadar. poder is permission or possibility: Posso nadar aqui? conseguir is managing, often against a difficulty: Não consigo nadar com essas ondas.
• Quero viajo ✗ → quero viajar. Only the first verb is conjugated.
• Quero para viajar ✗ → quero viajar. “To” is not translated.
• Preciso de sair ✗ → preciso sair. In Brazil, de goes before nouns only: preciso de um táxi. Before an infinitive it sounds European or very formal.
• dever gives advice (Você deve descansar) or makes a guess (Ele deve estar em casa: he must be at home). For a strict obligation Brazilians usually say tenho que, which you’ll meet in unit 8.
• In a café, Quero um café is fine among friends; Eu queria um café, por favor sounds softer.

If you speak Spanish

The structure is the same as in Spanish, so the traps are in the forms: quero (not quiero), posso and pode (not puedo, puede), devo (not debo), sei (not sé). Necesitar is precisar in everyday Portuguese, with de before a noun: preciso de ajuda. And for a guess, dever takes no de: ele deve estar em casa.