Past simple

Example:

George Washington led the American victory over Great Britain in the American Revolutionary War as commander-in-chief of the Continental Army in 1775–1783, and presided over the writing of the Constitution in 1787. In 1789 he became the first President of the United States. He died in December 1799.





Led, presided, became, died are all verbs in past simple tense.
Very often the verbs in past simple tense end in -ed
- I worked so hard yesterday.
- I studied very hard, to pass this exam.
- I called you two days ago.

Many verbs are irregular: the past simple in the irregular form does not end in -ed
examples:
go     -   went 
be     -   was
see    -   saw
think -   thought
tell    -   told

[ We will speak about irregular verbs in further Unit ]

In questions and and negatives we use did / didn't + infinitive
examples:
You saw           Did you see?           She didn't see
I said                Did you say?           I didn't say
They spent       Did they spend?       They didn't spend

You invited me for the party last week, but i didn't come.
Did you go to party last weekend? No I didn't go out.
Penny lost her mobile, so she didn't call me

In the following examples, do is the main verb in the sentence:
I didn't do my homework
Did she do the list?

The past of the verb to be is
I was                         I wasn't                       Was I?
You were                  You weren't                  Were you?
He/She/It was           He/She/It wasn't          Was He/She/It?
They were                 They weren't                Were they?

Note that we do not use did in negatives and questions with was/were
examples
Did you go out for dinner last night or you had food at home?
Yesterday she wasn't able to finish her work because she was so busy.