We meet every so often and compare notes.

我们时常碰头，交换意见。

Chelsea and I often compare notes.

切尔西和我经常互相交换意见。

Shall we compare notes now?

我们现在来对对笔记好吗？

We often compare notes after class.

下课后我们经常对笔记。

On Saturday night they met to compare notes.

星期六晚上他们碰头交换意见。