Learn the present and past tense of irregular verbs:
A verb is irregular if it does not have "ed" at the end
When it makes past tense.
 
Present tense Past tense
see saw
write wrote
give gave
sell sold
throw threw
fly flew
lose lost
say said
stand stood
think think
come came
leave left
pay paid
run ran
send sent
meet met
sleep slept
break broke
catch caught
fall fell