Past Contiuous and Simple Past : I was doing and I did

 Past Contiuous and Simple Past : I was doing and I did

A:

What happened?    The phone rang. (simple past)

What was Eric doing when the phone rang?     (past continuous)

He was reading a book.                                     (past continuous)

What did he do when the phone rang?                 (simple past)

He stopped reading and answered the phone.     (simple past)

Eric began reading before the phone rang.

So when the phone rang, he was reading. 

B: 

- Eric read a book yesterday.                                         - Eric was reading a book when the phone rang.

(= from beginning to end)

- Did you watch the movie on television                       - Were you watching television when I called you?

last night?

        

- It didn't rain while we were on vacation.                     - It wasn't raining when I got up.

- I started work at 9 o'clock and finished at 4:30. At 2:30 I was working.

- It was raining when we went out. (=It started  raining before we went out)

- I saw Lucy and Steve this morning. They were waiting at the bus stop.

- Mi ja fell asleep while was reading.

Reference : Basic Grammar in use