Can you keep quiet about it?

It's pointless to talk about it.

It is best to say nothing.

I told you it would work.

What were we talking about?

We were just saying that.

I'll do the talking.

Let me do the talking.

You have to think about the things you say.

I told you that before.

- When's your birthday? / Когда у тебя День Рождения?

- I told you that before. You don't remember? / Я тебе это раньше говорил. Ты не помнишь?

- No, my memory sucks. / Нет. У меня очень плохая память.

I have no idea what you're talking about.