1. myself

I always enjoy myself.
我总是玩得很开心。

I will find out the answer myself.
我自己会找出答案的。

I can do it myself.
我自己能够完成。

2. themselves

They're enjoying themselves.
他们玩得很开心。

They drove to France by themselves.
他们自己开车去了法国。

Let them find out the answers themselves.
让他们自己找出答案。

3. himself

He's enjoying himself.
他自己玩得很开心。

He can finish the work himself.
他自己能够完成任务。

He was talking to himself just now.
他刚才在自言自语。

4. herself

She's enjoying herself.
她自己玩得很开心。

Do you think she can do it herself?
你觉得她能够自己完成那件事吗?

She cut herself with a knife.
她用刀时切伤了自己。