Verbs: Modal
Eu devo ir!
Use the verb dever plus an infinitive to talk about obligations, possibilities, and suggestions.
Eu devo ir.
I must go.
Ela deve estar muito feliz.
She must be very happy.
Que roupa devo pôr?
What clothes should I put on?
Just add não to talk about prohibitions!
Ele não deve vir aqui novamente.
He must not come here again.
The verb dever by itself (with no infinitive) means to owe.
Nós devemos dinheiro.
We owe money.
O que poderia fazer?
Use poderia plus an infinitive to talk about unrealistic possibilities, or to make polite requests.
Como eu poderia saber?
How could I know?
Você poderia falar devagar?
Could you speak slowly?
You can also use the future forms of the verb poder to talk about future possibilities.
Nós não poderemos viver aqui para sempre.
We will not be able to live here forever.
Eu poderei ir amanhã.
I will be able to go tomorrow.
Eu quero porque quero!
Use the verb querer plus an infinitive to talk about things you want to do.
Você quer ser rico?
Do you want to be rich?
Quero ir para casa.
I want to go home.
You can use queria to talk about impossible wishes.
Eu queria ser mais jovem.
I wanted to be younger.
Finally, use querer in the past to talk about past intentions.
Ele não quis fazer isso.
He didn't mean to do that. (Literal: He didn't want to do that.)