Don't get nervous. There's nothing to get nervous about.

不要紧张，没什么好紧张的。

It's time to get nervous when nobody is nervous.

无人紧张时就应该感到紧张了。

I always get nervous about exams.

我考试时总是紧张。

Q: Do you ever get nervous on stage?

问：你在台上有时会感到紧张吗？

He began to get nervous.

他有点胆怯起来。