1. I go to the theatre once a year.
2. My parents clean the rooms twice a week.
3. My grandma watches TV once a day.
4. My mum makes cakes once a month.
5. My dad washes the car twice a month.
6. My friend goes to the sea once a year.
Достаточно?
He, She, It + глагол с окончанием s
I, We + глагол БЕЗ окончания s