Would appreciate if someone could help explain which of the following are grammatically correct:
A1. On which days do the shop open?
A2. On which days does the shop open?
B1. On which days are the shop open?
B2. On which days is the shop open?
I think the answer is A2 and B2 and my explanation is, we say 'On which days is he coming?" and not, "On which days are he coming?"
Is the explanation correct and is there a better way to explain?
A2 and B2 are correct. The subject of the verb is 'the shop'.