S + LAST + V2/ed = S HAVEN'T / HASN'T = THE LAST TIME + S + V2/ed + was +...when/...ago
3. I haven't been to Bristol for three years.
-> The last ......................................................................................................
-> I last ...........................................................................................................
4. I haven't been to London since 1972.
-> The last ......................................................................................................
5. I haven't gone swimming for 2 years.
-> The last ......................................................................................................
-> I last ...........................................................................................................
3. The last time I went to Bristol was three years
I last gone to Bristol three years ago
4. The last time I went to London was 1972
I last gone to London 1972 ago
5. The last time I went swimming was 2 years
I last gone swimming 2 years ago
1972 thì phải dùng "in 1972" chứ