例如：I was telephoning a friend when Bob came in.
例如：She didn’t want to stay in bed while the others were working in the fields.
He broke a chair while he was jumping up and down.
例如：I was cooking the dinner while he was playing the piano.
He called his mother every week even while he was traveling around the world.
例如：The bus had already left by the time I got there.
例如：By the end of last week, she had stayed in the west of China for two months helping the homeless children.
例如：He told me that he had already seen the film.
过去将来时（would do；was/were+ going to do）
例如：He said he was coming this evening.
I could get you a concert ticket.→Icould not/couldn‘t get you a concert ticket.
I was on the Internet when you called me.→I wasnot/wasn’t on the Internet when you called me.
The famous singer sang some Chinese songs.→The famous singer did not/didn’t sing any Chinese songs.
He could pack his things himself.→Could he pack his things himself?
Mr Li looked very old.→Did Mr Li look very old?
【技巧1】确定疑问词：人who/whom，物what，地点where，时间when/whattime，原因why，频率how often，长度how long，距离how far等等。例如：
They gave the concert last night.→When did they give the concert?
The accident happened near the station.→Where did the accident happen