1. have a grumble：抱怨

e.g. He has a grumble about being badly paid.

他抱怨待遇差。

2. cheer up：高兴起来，振作起来

e.g. Cheer up, I'm only trying to make you jealous.

别不高兴，我只不过想引你吃醋。

e.g. Cheer up, man. Things are not as bad as you think.

振作点，老兄。情况没你想的那么严重。

e.g. Cheer up. It'll all come right in the end.

想开些，到头来总会好的。

e.g. Cheer up! Our troubles will soon be over.

振作起来!我们的困难很快就会过去。