Question

past continuons
actions in the past continue past
singular (the wolf(subj) was(tobe) on the(complement)
(the boys(subj) were(tobe) playing(verb) soccer(complement)
past continuons
I cookies
SHE WAS playing
HE working
IT driving
YOU listening
WE WERE running
THEY sitting
YOU eating

Answer 1

Main use: We use present continuous tense to talk about interrupted and parallel actions.

Structure: Subject + was(for I,  she, he and it) /were(for you(singular and plural)  and they)

Examples:

1. I was watching tv when my mother rang. 

2. In 1999, I was studying at school, I was doing the pre suddenly I finished my clases  school.