PAST PROGRESSIVE

In (g): ist: I was walking down the street.

                                             2^nd: it began to rain.

Both actions occurred at the same time, but one action began earlier and was in progress when the other action occurred.

In (j): My studying began before 8:00, was in progress at that time, and probably continued.

Sometimes the past progressive is used in both parts of a sentence when two actions are in progress simultaneously.

a)      I was walking down the street when it began to rain.

b)      While I was walking down the street, it began to rain.

c)      Rita was standing under a tree when it began to rain.

d)     At eight o´clock last night, I was studying.

e)      Last year at this time, I was attending school.

f)       While I was studying in one room of our apartment, my roommate was having a party in the other room.