Question

2 I read / was reading a book when you called me / were calling me at 4 o'clock yesterday.​

Answer 1

I was reading a book when you called me at 4 o'clock yesterday.​

Мы используем комбинацию past continuous + past simple что бы показать, что длительное активити было прервано коротким, в данном случае "called"

Answer 2

Both sentences are grammatically correct, but they convey slightly different meanings based on the tenses used:

1. "I read a book when you called me at 4 o'clock yesterday."

   • In this sentence, you are using the past simple tense ("read") to indicate that you completed the action of reading the book before the phone call at 4 o'clock.

2. "I was reading a book when you were calling me at 4 o'clock yesterday."

   • In this sentence, you are using the past continuous tense ("was reading" and "were calling") to indicate that both actions were happening simultaneously. You were in the middle of reading the book when the phone call was happening.

The choice between these two sentences depends on the specific emphasis or nuance you want to convey. Sentence 1 suggests that reading the book and receiving the call were two separate actions, while sentence 2 suggests that they were happening at the same time.