1.I haven't really enjoyed myself since your birthday party.
2.My father hasn't seen his brother for 20 years.
3.Tom has gone to Scotland since last Friday.
Ta có:
1.The last time+S+V-ed/V2+was+time.
=Time+was+the last time+S+V-ed/V2.
=S+haven't/hasn't+V-ed/P2+since+time.
2.It's+time+since+S(+last)+V-ed.
=S+haven't/hasn't+V-ed/P2+for time.