语法总结
过去进行时 + 一般过去时
I was having dinner ... when Tony came in 和 While he was eating, I asked him... 都是“长动作做背景，短动作切入”的典型结构。
相似句：
- I was reading when the lights went out.
- While she was cooking, the baby cried.
现在完成时表示“到目前为止从未发生”
He has never borrowed money from me / I have never borrowed any money from you 都是在说“截至现在，从来没借过”。
相似句：
- I have never seen the film before.
- She has never been to Japan.
borrow / lend / pay back / pay for
borrow 是借入，lend 是借出，pay back 是还钱，pay for 是为某物付费。本课正好把四个动作串成完整金钱往来链条。
相似句：
- Can I borrow your pen?
- I'll pay for the tickets and you can pay me back later.
ask sb. to do sth.
I asked him to lend me twenty pounds 中 ask 后面不能直接接动词原形，要用不定式结构。
相似句：
- She asked me to wait outside.
- The teacher asked us to be quiet.