How long had you been working when you stopped for a break?
I'd been working since/for... when I stopped for a break.
When did you last buy groceries?
I last bought groceries...
What were you doing at this time yesterday?
I was + ver+ing...
How long had you been sleeping when your alarm clock rang this morning?
I'd been sleeping for / since ...
What had you done before you got home last night?
I had + past participle
What unusual food have you tried?
I've tried... / I've never tried any unusual food.
How many books have you read this year?
I've read ... books this year. / I haven't read any.
Where did you have lunch yesterday?
I had lunch at...
Had you had a shower before you left home this morning?
Yes, I had. / No, I hadn't.
How long have you been living at your present address?
I've been living at my present address since/for...
Have you ever ridden a horse?
Yes, I have. / No, I haven't. / No, I've never ridden a horse.
Were you working at 10 a.m. yesterday?
Yes, I was. / No, I wasn't.
Has it ever snowed in this country?
No, it hasn't. / Yes, it has.
What have you been doing regularly lately?
I've been verb+ing
What haven't you done this month?
I haven't + past participle