1. I DID this exercise yesterday.
2. I HAVEN'T DONE this exercise yet.
3. We HAVE GONE to school since the first form.
4. We DIDN'T GO to school last Monday.
5. You RODE a horse last week.
6. You HAVE NEVER SEEN a horse.
7. He HASN'T WASHED the dishes yet.
8. He BROKE this cup a minute ago.