علل ناقص ضمیری در ساختار جمله "do it or else"

معانی or else: یا اینکه، وگرنه (به عنوان هشدار یا تهدید) 

تعریف دقیق: 

used to introduce the second of two alternatives.

e.g. "he always had a cold or else was getting over an earache"

•   in circumstances different from those mentioned.

e.g. "they can't want it, or else they'd request it"

•   used as a warning or threat.

"e.g. "you go along with this or else you're going to jail
 

میتونه  دستوری باشه:

 Do it or else...

یا گزاره‌ای (خبری):

 You'll do it or else...

(این کار را انجام خواهی داد) وگرنه...