1) My parents (did not write) a letter.
2) We (did not go) to school yesterday.
3) We (went) to school last week.
4) I (bought) an ice cream yesterday.
5) I (did not play) the piano yesterday.
6) The students (took) the books.
7) My brother (played) football.
8) My mum (did not buy) milk yesterday.
9) Mary (did not do) homework.
10) My friend (helped) me a lot.