1. I didn`t go to school,
2. Helen didn't wash the dishes.
3. Alex didn't play tennis.
4. My mother didn't write a letter.
5. We didn't buy flowers.
6. I didn't eat dinner.
№4
to go/ went/ didn't go
to buy/ bought/ didnt buy
to study/ studied/ didn't study
to wash/ washed/ didn't wash
to eat/ ate/ didn't eat
to play/ played/ didn't play
to write/ wrote/ didn't write