Past Progressive (Past Continuous)

Definition : 

The past progressive puts emphasis on the course of an action in the past.

Form : 

Exceptions in Spelling : 

Exceptions in spelling when adding ing	Example
final e is dropped (but: ee is not changed)	come – coming (but: agree – agreeing)
after a short, stressed vowel, the final consonant is doubled	sit – sitting
l as final consonant after a vowel is doubled (in British English)	travel – travelling
final ie becomes y	lie – lying

Use of Past Progressive : 
puts emphasis on the course of an action in the past
Example: He was playing football.

two actions happening at the same time (in the past)
Example: While she was preparing dinner, he was washing the dishes.

action going on at a certain time in the past
Example: When I was having breakfast, the phone suddenly rang.

Signal Words of Past Progressive : 

when, while, as long as