+0
What were you doing? This is a past continuous question but it doesn't have a second second part to it?

So if I were to reply with...I was watching televsion.

Would it be considered proper grammar?
+0
Yes.

BTW, It's the same as what are you doing placed in the past. But while 'what are you doing' implies 'now' what were you doing needs a time reference of some kind so I assume that something must have preceded the question.

If you were to say 'What were you doing last night at 8'' that would certainly make sense. To just say 'what were you doing' without any prior context, would be wrong.
+0
What's missing is a situational reference.

What were you doing in my office (just now)?
What were you doing when the murder took place?
What were you doing when the phone rang?
What were you doing while your kids were prank calling emergency services?

There's a bit more suspicion attached to the words than simply what "What did you do?"

What did you do on your vacation?
What did yo do when you visited Paris?
What did you do on your night off without the kids?
Students: We have free audio pronunciation exercises.
Comments  
IvanhrYes.

BTW, It's the same as what are you doing placed in the past. But while 'what are you doing' implies 'now' what were you doing needs a time reference of some kind so I assume that something must have preceded the question.

If you were to say 'What were you doing last night at 8'' that would certainly make sense. To just say 'what were you doing' without any prior context, would be wrong.

Can you say: What were you doing at home? Even though it doesn't seem to indicate an interruption in time.
 BarbaraPA's reply was promoted to an answer.
Teachers: We supply a list of EFL job vacancies

Yes, it's absolutely correct.

Because you're still referring to what happened last night.

Maybe you don't realize it, but you are answering a question that was asked and answered many years ago. The OP has not been active on our forum since 2010.

Why not answer questions that are more recent? That way there's a better chance that the person who asked the question is still participating on our forum and can benefit from your answer.

CJ