Verb forms

The form of any verb in English is made up of two things:

1. Time frame:

    Tells when something took place. There are three basic time frames:

  • present
  • past
  • future.

2. Aspect:

   Tells how the verb is related to that time, or gives some other information about the quality of the action.  Aspect denotes 
   whether or not the event has occurred earlier (perfect aspect) or is still in progress (progressive aspect); in other words, a situation
   may be represented as fixed or changing; it may be treated as lasting for only a moment or having duration, and it can be viewed as
   complete or as ongoing.
 

ASPECT

MEANING

simple

at that time

progressive

in progress during that time

perfect

before that time

perfect progressive

in progress during and before that time
 


Examples:

  • This computer works perfectly (permanent state).
  • This computer is working perfectly (temporary state).
  • I worked as Sessional instructor at SFU for two years (complete).
  • I have been working as a Sessional instructor since September 2006 (in progress during and before).
     

Overview of the tense-aspect system

When we combine the three time frames and the four aspects, we get 12 possible combinations of forms (tenses),
and the name of each tense tells which time frame and which aspects are being used.
 

ASPECT

SIMPLE

PERFECT

PROGRESSIVE

PERFECT PROGRESSIVE

TIME FRAME

 

have + -en

be + ing

have + -en    be + -ing

Present

simple present

walk/walks

write/writes

present perfect

has/have walked

has/have written

present progressive

am/is/are walking

am/is/are writing

present perfect progressive

has/have been walking

has/have been writing

Past

simple past

walked

wrote

past perfect

had walked

had written

past progressive

was/were walking

was/were writing

past perfect progressive

has been walking

had been writing

Future

simple future

will walk

will write

future perfect

will have walked

will have written

future progressive

will be walking

will be writing

future perfect progressive

will have been walking

will have been writing
 

Keeping tenses in the same time frame

In general, we choose a particular time frame and then choose from among the tenses within that time frame in order to describe events.
 

EXAMPLES

EXPLANATIONS

My roommate had (simple past) a dance party last Friday night. I
was working (past progressive) that night, so I didn’t (simple past) get home until 10:00, and everyone had already started (past perfect) dancing.

Use past tense to describe things that happened at a specific time in the past.

My roommate has (simple present) a dance party every Friday night. I work (simple present) on Friday nights, so I don’t (simple present) get home until 10:00, and everyone has already started (present perfect) dancing.

Use present tense to describe things that are happening now, are related to now, or happen again and again.

My roommate is going to have (future progressive) a dance party next Friday night.  I will be working (future progressive) next Friday night, so I won’t (simple future) get home until 10:00, and everyone will already have started (future perfect) dancing.

Use future tenses to describe events that are going to happen at some time in the future



Changing the time frame within a passage
 

EXAMPLES

EXPLANATIONS

There are many examples in history of increasing military power causing a decreasing standard of living. Rome was unable to feed both its army and its population. Great Britain declined steadily from its economic position in the early part of this century.

To move from a general statement to specific examples

One hundred years ago the life expectancy in the United States was about sixty-five. Nowadays, it has increased by an average of ten years.  In the next century, if current trends continue, people should be able to live until their nineties. Interestingly enough, however, a hundred years ago the number of people who were over one hundred was less than one percent of the population.  That figure has not changed substantially, even today.

To show contrast between one time and another

(Burnaby, B.C). – It was an improved performance by the Simon Fraser University Clan football team on Tuesday night, as they held the University of British Columbia Thunderbirds in check for three and a half quarters; however, the Clan left Thunderbird stadium on the losing side, falling 19-11 to the T-Birds.   Simon Fraser drops (general truth) to 0-2 on the season.

To make a statement of general truth