English Grammar - Tense

Simple Present for

Habitual action in the present / Jan rides her bicycle to school everyday.
Condition that is always true / I am not a morning person.
Timeless general truth / Water boils at 100C.
Referring to text & quotations / In his article, Chomsky says ~
 

Present Progressive for

Action or activity happening at this moment, today, this year, etc. / Sean is majoring in linguistics
Temporary habit / Mark is working for his uncle for now (and probably his going to move)
Action in progress at a specified point of time / I'm usually reading news article when I web-surf


Simple Past for

Action happened at a specific time in the past / I visited Korea last year
Action happened over a period of time in the past with the implication that it is no longer true in the present/ I lived in LA for 15 years


Past Progressive for

Action in progress at a specified point of time in the past / At 8 PM last night, I was studying in the library
Or was interrupted at a specified point of time in the past / I was cooking when the phone rang
To emphasize on the duration of an action lasted for a period of time in the past / He was cooking while you were out


Present Perfect

To express an action or state began in the past and continues in the present / have lived;known & since;for
For resultative in the present / I have already filed my income taxes
For updated information for the listener / I have just completed the application, FYI
Experience able to happen again / Susan has seen the doctor several times
To express prior time of a to-clause than the main clause / I'm sorry not to have done it
 


Present Perfect Progressive

Perfect → Perfect Progressive to emphasize the duration / I've been living here for 2 years
To update information that has been in progress recently / Sean has been reading;thinking about it


Past Perfect

To indicate an action was completed before another action began in the past / I had done it before ~
Or by a definite time in the past /  I had read a book by last month since Jan. this year
* In a 'before' or 'after' clause Simple Past can replace Past Perfect / After I (had) left, ~


Past Perfect Progressive

To emphasize the duration of an action that had happened / I had been waiting for you for 2 yrs when ~ 


Future

To express an action, event, or state will occur in the future / I'll drive you to the airport
* Don't use Future tense in a future adv. clause / When you get up, I'll make you a cake
* But in noun clauses, you can use Future tense / I wonder when it will fall.


Future Progressive

Action happening over a period of time at some specific point in the future / I'll be studying when you call
To emphasize the duration of an action in the future / Lin will be working on the topic for the next week


Future Perfect

An action completed before another event or time in the future / I'll have done it by the time he comes
* Attention to 'by', 'until', and 'before'


Future Perfect Progressive

To emphasize the duration of an action in the future / By this time next year, I'll have been doing it for 2 yrs
* Attention to 'before', 'by', 'until', and 'for'