Prepositions and Time Words
Specific Time: "When?" (Use simple tenses.)
Mr. Barnes is watching television now.
While he was watching television, the phone rang.
He will be watching television tonight when his wife gets home.
Duration: "How Long?"
I have finished my homework already. (before now)
After I had finished my homework, I started to cook dinner.
I will have finished my homework, when I start to cook dinner.
Ago follows time word(s) and is used to indicate the amount of time before the present:
Words indicating actions occurring at the "same" time (or nearly the same time)
Words indicating actions occurring at "different" times
design by web design company