act up

If a child is acting up， they are behaving badly.

如果一个小孩子act up，那就是说他表现的很差，故意捣乱的意思。

I could hear Jonathan acting up downstairs.

我能听见乔纳森在楼下撒泼。

If you act up in class， you will be sent to the principal‘s office。

如果你在课堂上调皮捣蛋，就会被送到校长办公室.

The driver stopped the school bus because the kids were acting up.

因为孩子们调皮捣蛋，司机把校车停了下来。