Acho que sim

acho que sim is I think so, and it is probably the most useful three words in this session. acho que não is I don't think so. Between them they answer half the questions you will be asked.

The verbs of thinking

Portuguese has several verbs where English mostly has one, and they are not interchangeable.

• achar is to think, in the sense of to reckon. It is the everyday opinion verb: acho que ele está certo.
• pensar is to think in the sense of to consider or to have thoughts: estou pensando, I am thinking. pensar em is to think about.
• acreditar is to believe, and acreditar em is to believe in. crer means the same but sounds bookish or religious.
• parecer is to seem: parece que vai chover, it looks like rain.
• supor is to suppose, and it conjugates like pôr.

achar also means to find, which is where the opinion sense comes from: what do you find about this?

How sure you are

certeza is certainty, and tenho certeza is I am sure, literally I have certainty. dúvida is doubt: sem dúvida is without a doubt. claro is of course, and provavelmente is probably.

certo is right or correct, errado is wrong. está certo doubles as fine or all right, a bit of agreement dropped into the conversation.

What backs the opinion up

opinião is opinion, ideia is idea and verdade is truth. razão is reason, and ter razão is to be right: você tem razão, you are right. você está certo means the same, but ter razão is the one that settles an argument.

Agreeing and disagreeing

concordar is to agree, and concordar com is to agree with. acordo is an agreement, and de acordo is agreed or in agreement: estou de acordo.

discutir is to discuss, and also to argue. Which one depends on the tone of voice, which is very Brazilian.

embora is although, and it takes the subjunctive: embora ele tenha razão, although he is right. It is the word that lets you concede a point before making your own.