我同意！

Wǒ tóngyì!

I agree!

你同意吗？

Nǐ tóngyì ma?

Do you agree?

我妈妈同意让我去参加比赛了。

Wǒ māma tóngyì ràng wǒ qù cānjiā bǐsài le.

My mother agreed to let me participate in the competition.