Time expressions are used to indicate the time at / during which an action took place. Common time expressions include:

Present forms: everyday, on Fridays, at the moment, now, as well as adverbs of frequency such as always, usually, sometimes (for present habits and routines). Days of the weeks followed by "s" such as Mondays, Tuesdays, etc.

Examples

He sometimes finishes work early.
Marjorie is listening to the radio at the moment.
Peter goes jogging on Saturdays.

Past forms: when I was ..., last week, day, year, etc., yesterday, ago (two weeks ago, three years ago, four months ago, etc.)

Examples

He visited his friends last week.
I didn"t see you two days ago.
Jane flew to Boston yesterday.

Future forms: next week, year, etc., tomorrow, by (the end of the week, Thursday, next year, etc.) in X time (in two weeks time, in four months time, etc.)

Examples

I"m going to attend a conference next week.
It won"t snow tomorrow.
They"re going to visit New York in two weeks.

Perfect forms: since, yet, already, just, for

Examples

Michael has worked here since 1998.
Have you finished reading the paper yet?
He"s just gone to the bank.