1.We began eating when it started to raining. đã có to rùi mà còn V-ing:boxing:)
=> We have begun eating before it stared raining
2.This is the first time I had such a delicious meal .
=> I haven’t ever had a such delicious meal before
3. I haven’t seen him for 8 days.
=> The last time I saw him was 8 days ago
4. I haven’t taken a bath since Monday.
=> It is A LONG TIME I DIDN'T TAKE A BATH
OR: IT IS MANY DAYS I DIDN'T TAKE A BATH….