It's 2 years since I was last in Rome.
~ I haven't .been in Rome for 2 years.......

 I saw Tom last on his wedding day 
~ I haven't .......seen Tom since his wedding day........
 

I last ate raw fish when I was in Japan
~ I haven't ....eaten raw fish since I was in Japan..........
 

It's years since Mary last spoke French
~ Mary hasn't .....spoken french for years......
 

It's ten weeks since I last had a good night sleep 
~ I haven't.......had a good night sleep for 10 weeks.........