serez parties vs serez sorties

Question

why is partir right ans sortir wrong pleas. i thought sortir is to go out so would be acceptable here, but isn'tis for same question as below, will you have left by 4 oclock

Accepted Answer

Hi Carol,
The verbs 'sortir' and 'partir' are often confused but they mean different things.

sortir= to go out / to come out
partir = to leave / to go

The actual Kwiz question was:
Vous ___ à quatre heures ? ( Will you have left at 4 o'clock ?)
So partir is correct here and not sortir. 
Hope this helps!

Answer

Hi Carol,I haven't looked at the text, but the first thing that comes to my mind is the issue of transitivity.Partir does not take a direct object. Sortir can take a direct or indirect object depending upon whether used with avoir or être.Is this the key to your query?Jim