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I.  FORMATION OF TENSES

Simple Present - simple form of the verb; add -s to third person singular       

     I study every day.  She studies every day.

Simple Past - simple form + -ed

     I studied last night

Simple Future - will + simple form

     I will study tomorrow

Present Perfect - have, has + past participle (-ed, -d, -en, -n, -+)

     I have already studied that book

     He has already studied that book

Past Perfect - had + past part

     I had already studied Unit 1 before I began to study Unit 2

Future Perfect - will have + past participle

     I will have studied Unit 4 before I study Unit 5

Present Progressive - am, is, are + present participle (-ing form)

     I am studying right now.  He is studying... We are studying..

Past Progressive - was, were + present participle

     I was studying when you called.  We were studying when you

     called     

Future Progressive - will be + present participle

     I’ll be studying when you come

Present Perfect Progressive - have, has been + present participle

     I have been studying since 1600 hours

     He has been studying for four hours

Past Perfect Progressive - had been + present participle

     I had been studying for two hours when you called

Future Perfect Progressive - will have been + present participle

     I will have been studying for two hours by the time you get

     here   

II.  USE OF TENSES

Present Tense:

1.   to express a condition that exists at the moment of speaking and may continue for a short time, or to express a general truth.

2.   to express the idea that an activity or capability existed before the moment of speaking, exists at the moment of speaking, and may continue for a long time.

3.   to express a customary action; adverbs of frequency are often used to express this concept of time, (i.e. often, frequently, usually, etc.).

4.   to express future time, usually occurs with adverbs of time.

5.  to increase the vividness of a story.

Past Tense:

1.   to express activities that occurred at a definite time in the past;

·         usually a specific time word is used

·         yesterday      last night   a year ago

·         in 1985           last year             before I left home

2.   to express activities that occurred at an unspecified time in the past, which is implied or understood from the context.

3.   to express an activity that occurred in the past over a continuous period of time, but did not continue to the present moment of speaking.

Present Perfect:

1.   to express an activity that has lasted from a stated point  of time in the past up to the present moment.

2.   to express an activity that has lasted from an indefinite time in the past up to the moment of speaking.

3.   to express an activity that has occurred one or more indefinite times in the past but does not continue to the present moment of speaking.

4.   to refer to an activity that has been completed a short time before the moment of speaking.

Past Perfect:

1.   to express the occurrence of an event in the past that occurred before another event in the past; frequently, when the past perfect is used in the main clause, the past tense is used in the subordinate clause.

Future Perfect:

1.   to express the completion of a future act as past or completed in relation to a stated or implied future time.

Present Progressive:

1.   to express activities that are in progress at the moment of speaking.

2.   to express an activity that occurred at various intervals in the past and will probably continue at intervals in the future, but is not necessarily continuous.

3.   to express an activity that will take place in the future, which is indicated by a time expression.

Past Progressive:

1.   to show tat an activity was in progress in the past when another activity occurred.

Future Progressive:

1.   to express an activity that will be in progress in the future.

Present Perfect Progressive:

1.   to emphasize the continuous nature of an activity that has lasted from a time in the past up to the moment of speaking.

Past Perfect Progressive:

1.   to emphasize the continuous of a past action that occurred immediately before another action in the past.  Often the second action stops or interrupts the first action.

Future Perfect Progressive:

1.   to express an activity in progress, of which a measurable phase or period will be completed at a particular time in the future

III.  EXAMPLES

Simple Present

I study everyday.

He eats lunch in the dining hall.

Simple Past

I studied last night.

He ate breakfast this morning.

Simple Future

I will study tomorrow.

He will eat breakfast tomorrow morning.

Present Perfect

I have already studied that book.

He has already eaten breakfast.

Past Perfect

I had already studied Unit 1 before I began to study Unit 2.

He had eaten breakfast before he came to class.

Future Perfect

I will have studied Unit 4 before I study Unit 5.

He will have eaten breakfast before class begins.

Present Progressive

I am studying right now.

He is eating breakfast in the dining hall.

Past Progressive

I was studying when you called.

He was eating breakfast when the bell rang.

Present Perfect Progressive

I have been studying since 1600 hours.

He has been eating breakfast at 0700 for 5 years.

Past Perfect Progressive

I had been studying for 2 hours before you called.

He had been eating for 15 minutes when his friend

joined him.

Future Perfect Progressive

I will have been studying for two hours by the time

you get here.

He will have been eating in the dining hall for 3 months

by the time he graduates.