جمل احدثت دويا في الوسط اللغوي(للاساتذه فقط)...find the mistake

[Samy Farid Mekhael]

Before leaving............................ . .g
The second sentence is right
Has been cooked

[Mr. ayman]

المشاركة الأصلية كتبت بواسطة Samy Farid Mekhael

Before leaving............................ . .g
The second sentence is right
Has been cooked

اذا متي تختلف before عن by the time
الا نقوم بشرحهما كحد سواء
لذا
اخي الحبيب
لا يجوز استخدام لاغ by the time - as soon as كحروف جر
before i studied, i
before studying, i

but

by the time i studied, i
by the time studying, i ............. X
reference:
A tit for tat preview of grammar
first edition- By Bufferlet S Blain. page 128
regards