present action or condition

general truths

non-action; habitual action

future time

• I hear you.

• Here comes the bus.

• There are thirty days in September.

• I like music.

• I run on Tuesdays and Sundays.

• The train leaves at 4:00 pm.

activity in progress

verbs of perception

• I am playing soccer now

• He is feeling sad

completed action

completed condition

• We visted the museum yesterday.

• The weather was rainy last week.

past action that took place over a period of time

past action interrupted by another

• They were climbing for twenty-seven days.

• We were having dinner when she told me.

With will/won't -- Activity or even that will or won't exist or happen in the future

With going to -- future in relation to circumstances in the present

• I'll get up late tomorrow.

• I won't get up early.

• I'm hungry.

• I'm going to get something to eat.

With verbs of state that begin in the past and lead up to and include the present

To express habitual or continued action

With events occuring at an indefinited or unspecified time in the past -- with ever, never, before

• He has lived here for many years.

• He has worn glasses all his life.

• Have you ever been to Tokyo before?

To express duration of an acton that began in the past, has continued into the present, and may continue into the future

• David has been working for two hours, and he hasn't finished yet.

to describe a past event or condition completed before another event in the past

In reported speech

• When I arrived home, he had already called.

• Jane said that she had gone to the movies.

to express action that will be completed by or before a specified time in the future

• By next month we will have finished this job.

• He won't have finished his work until 2:00.