To chip in. It means to contribute a small amount of money to a pool that will be used to buy something. The translation to this expression would be something like "To make a little cow", and the reason why a cow is used in this expression is probably associated with the cow animal from the Jogo do Bicho.
- Vamos precisar de 100 kilos de isopor pra fazer a maquete.
- Hmmm. Acho que vamos precisar fazer uma vaquinha pra comprar tudo isso de isopor.
"Keep an eye on the fish, and the other on the cat". This expression is used to denote special attention to something.
You can use this expression when you have to work on something, but must pay attention to something else. Or when you want to tell others that you will pay attention to everything.
This expression can also be used when a person has eyes that look in different directions from each other, as in "one eye on the pot and the other up the chimney".
- A professora aplicou a prova ontem e ficou com um olho no peixe e o outro no gato. Nem deu pra colar.
It is used to say that someone is welcome to come back, that it has been a pleasure and that the hosts would like the guests to come back or visit often. The literal translation is Come back always.
- Obrigado pelo chá! Tchau tchau.
- Obrigada você! Volte sempre.
It means "Go with God" and is used when saying good bye to someone. It doesn't matter whether you'll see that person soon or not. Some people have the habit of always saying these words to people they care.
"Fica com deus" has the same meaning.
- Tchau pai
- Tchau Junior. Vai com deus.
I insist. It is a very polite way of saying that you insist on doing some favor.
You can use it when you want to let someone else to sit on your place (like on buses, metro, etc) and s/he denies saying that she isn't tired or doesn't need.
Similarly, when you volunteer to do something and others say that you don't need to. You just say "Faço questão", or "Eu faço questão", and they will understand that you really mean it.
- Ih! Esqueci o boleto lá em cima!
- Pode deixar que eu pego.
- Ah, não precisa não. Deixa pra lá.
- Pode deixar. Faço questão.