GRAMMAR

PAST CONTINUOUS

Affirmative:                                                     

I was working
you were working                                                                 

he/ she/ it  was working                                                       

we/ you /they were working          
                                        

Negative:   

I was not (wasn't) working
you were not (weren't) woring
he/ she/ it was not (wasn't) woring
we/ you /they were not (weren't) working

Interrogative:

Was I  working ?
Were You  working ?

Was he/ she/ it working ? 
Were we/ you/ they working ?

Uses: 

•  An incomplete action in progress at a specific time in the past
•  An incomplete action interrupted by another action 
•  Two incomplete actions in progress at the same time in the past 
•  express a long action was in process when a short occured. The long is preceded of  ''while'' or ''as'' and the short of  ''When''. 
• express several actions occur simultaneously in the past, in this case they are joined by while or as
•  With the adverbs "always" to denote complaint : "he was always telling me what to do''

Adverbs of frequency / Time expressions 

last night/ week/ year , at 4 o'clock, when, while, as.

Examples 

My sister was working as a tour guide. 
Alex wasn't travelling 
They were learning to ski last year
The plane was taking off as I was driving to the airport
He was always talking about his trips.