With regular verbs you make the simple past by adding '-ed'.
Unfortunately, there are a number of irregular verbs and with those, this rule doesn't apply.
The irregular verbs have their own form that you have to memorize/study.
|
present tense |
past tense |
|
to be |
was/were |
|
to buy |
bought |
|
to come |
came |
|
to do |
did |
|
to drink |
drank |
|
to eat |
ate |
|
to feel |
felt |
|
to find |
found |
|
to get |
got |
|
to give |
gave |
|
to go |
went |
|
to know |
knew |
|
to leave |
left |
|
to make |
made |
|
to meet |
met |
|
to read |
read |
|
to say |
said |
|
to see |
saw |
|
to sit |
sat |
|
to sleep |
slept |
|
to take |
took |
|
to teach |
taught |
|
to tell |
told |
|
to think |
thought |
|
to understand |
understood |
|
to wear |
wore |
|
to write |
wrote |
You can find various lists of irregular verbs on the internet.