grammar question

[haseli22]

Dear teachers,

Would you please tell me which item fills the blank?

Not until the thief left the house, ...................... him although they were at home.
a. did they notice b. neither did they notice c.they didn't notice

Thanks.

 

[Chicken Sandwich]

Which do you think is the right answer and why?

 

[haseli22]

I think the first item is correct.

 

[5jj]

I think the first item is correct.

So do I. Was that a guess on your part, or do you understand why?

 

[haseli22]

It was a guess and some reasoning! I focused on the meaning of the sentence and it was like this :
"When the thief was inside the house, they didn't notice him, but the moment that the thief left the house, they realised that there was a thief there."
Am I right in understanding the meaning of the sentence?

 

[5jj]

You have understood the situation correctly.

When we begin a sentence with a negative adverbial, word, phrase or clause, we generally have an auxiliary verb before the subject:

Not until the thief left the house did they notice him.
Never have I seen such a beautiful sight.
Only when (= not until) she took off her coat could they see the famous diamond

 

[haseli22]

Thanks a million for your nice explanation!