I imagined myself talking to a doctor in English, so I made up this conversation.
A: You should take this medicine before the meals.
B: ................? (Here, I need a question that would require the doctor to specify a certain time)
A: 2 hours before the meals.
This kind of conversation is often used in daily life. However, I could not be sure how to ask about the amounf of time when it comes to specify the beforeNESS with regards to the time of medication.
I think of the following alternatives:
1- How much before?
2- How earlier?
3- How much earlier?
4- How long earlier?
I think number 1 sounds good to me as a non-native speaker, but the others also seem to make sense grammatically. However, I can't be sure. So, which one would be the most common or the most correct?