Błędy w zdaniach - proszę o sprawdzenie i korekte

Witam,
Oto polecenie zadania:
Correct the sentences if necessary:
1. I haven't seen Peter since he has begun seeing his girlfriend.
moja wersja: I haven't seen Peter since he begun seeing his girlfriend.
2. They will join us after they will have sth to eat.
They will join us after they have sth to eat.
3. I need to be home early today, so I'm leaving at 4 -> myślę, że to jest poprawne
4. Ever since we met you never asked me what I prefer to do.
Ever since we met you have never asked me what I prefer to do.
5. How long have you got a dog?
How long have you been getting a dog?
6. In all my life I never spoke to someone who is so stupid.
In all my life I have never spoken to someone who is so stupid.
7. This is the only occasion I've seen him wearing a tie. -> it's correct
8. By the time he is fifty he will live in his country for half his life.
By the time he is fifty he will have been living in his country for half his life.
9. She looks very pale. I think she will faint.
I think she is going to faint.
10. Since he has lived here, he is usually extremely friendly.
Since he lived here, he has usually been extremely friendly.

Proszę o sprawdzenie i korekte. Zdania potrzebne mi są jak najszybciej, a nie jestem pewna czy dobrze je poprawiłam
Pozdrawiam, Madis.

1 jaka jest forma simple past od begin?
2 ok albo have had
3 4 ok
5 od jak dawna dostajesz psa? :-)
have you had a dog
6 7 8 9 ok
10 jezeli nadal tu mieszka, to since he has lived jest ok
druga czesc zdania dobrze poprawiona

czyli 1. I haven't seen Peter since he began seeing his girlfriend.
a 5.How long have you had got a dog?

Bardzo dziękuję za pomoc

5 nie. Napisalem, jak jest poprawnie

future perf. doesn't apply in # 8?

Aha. Ok, dziękuję

To bylo pytanie:)