Simple Tense
Verb tense tells you when the action happens. There are three main verb tenses: present, past, and future. Each main tense is divided into simple, progressive, perfect, and perfect progressive tenses.
	Present	Past	Future
Simple	finish	finished	will finish
Progressive	am/is/are finishing	was/were finishing	will be finishing
Perfect	have/has finished	had finished	will have finished
Perfect Progressive	have/has been finishing	had been finishing	will have been finishing
Things to remember about simple tense:
     a. Present tense is the original verb form.
     b. Past tense has a few patterns.
     c. Future tense needs will (shall) + verb.
run
    I run a marathon twice a year. (present)
    I ran a marathon last year. (past)
    I will run a marathon next year. (future)
eat
    I eat lunch in my office.
    I ate lunch an hour ago.
    I will eat lunch in one hour.
see
    I see a movie once a week.
    I saw a movie yesterday.
    I will see a movie tomorrow.
know
    I know it.
    I knew it the day before yesterday.
    I will know it by tomorrow.
learn
    I learn English.
    I learned English the last two years.
    I will learn English next year.
cook
    I cook my supper every night.
    I cooked our dinner already.
    I will cook breakfast tomorrow.
[Quiz 10.1]
Fill in the blanks with appropriate verb forms.
1)I                      a song at the concert yesterday.
2)He                      a letter to his girlfriend tomorrow.
3)I                      to the library to borrow some books this weekend.