1. The last time I played tennis was in 1990.
⇒i haven't played tennis since 1990
2. It’s three years since I saw Nam.
⇒i haven't seen nam for 3 years
3. The last time I saw her was in 2006.
⇒i haven't seen her since 2006
4. She bought that house in 1994.
⇒she has bought that house since 1994
5. Nam hasn’t gone swimming since 2010.
⇒the last time nam went swimming was in 2010