The past simple verb form is used to talk about events in the past; it’s often used to tell a story.
He walked into the room and looked around. There was a knock on the door. He opened it and saw…
I woke up. I got out of bed. I dragged a comb across my head…
In general we use it to talk about an event which started and finished in the past:
The Big Bang happened several million years ago.
In 1588 the Spanish Armada sailed for England.
The Beatles released Sgt. Pepper’s Lonely Hearts Club Band in 1967.
Form
We make the past form of regular verbs by adding -ed to the infinitive. There is no change for the third person singular:
{subject} + {past form}
I worked hard.
She walked to the supermarket.
They laughed at the joke
If the verb ends in a stressed vowel + consonant then double the final consonant:
stop > stopped
tip > tipped
If the verb already ends in -e then just add the -d:
love > loved
pile > piled
If the verb ends in consonant + -y then take off the -y and add -ied:
pity > pitied
sully > sullied
Irregular verbs follow no simple rule to make the past simple form. Each irregular verb has its own past simple, and these can only be learned by heart, for example:
Present – Past
eat – ate
find – found
go – went
see – saw
tear – tore
Useful links
Grammar Foundation Course – for a thorough grounding in English Grammar
IWeb TEFL Grammar Guide – a invaluable resource on anything and everything to do with English grammar