及物动词
1. He answered that he knew nothing about it.
他答道他不知道这件事。
2. Don't answer (me) back; it's not polite.
不要跟我顶嘴，这是不礼貌的。
不及物动词
1. How would you answer the criticism made of your work?
你对针对你的工作提出的批评作何辩解？
名词
1. I'm waiting for an answer to my letter.
我正在等候回信。