# Asking 'How long from now?'

Can someone help me understand how I should ask someone how long from now something happens? These below structures are the ones that come to my mind although I'm not sure if they sound natural to native speakers. Please let me know if you use a different way to inquire about this information. What's your preferred structure?

A - How long from now will you need (be needing?) the book?

B - How long will you need the book from now?

C - How many hours will you need the book in? (This one sounds weird to myself.)

D - In how many hours (In how long) will you need the book?

E - How long till you will need the book?

F - How long will you need the book till?

• Unless the context strongly indicates some other frame of reference, How long? in respect of a time duration always refers to a span of time that either ends now (How long have you been here?) or starts now (How long will you be here?). So all of your suggestions are unnecessarily complicated - just ask How long will you need the book? Commented Jan 5, 2017 at 19:16
• @FumbleFingers but I don't need to know 'How long will they need the book ?' They don't need the book jow. What I need to know is within what duration of time will they need the book. Commented Jan 5, 2017 at 19:34
• Well, if it's contextually known that they don't need the book now, surely the speaker can only be asking how long they'll need it starting from when they take possession of it, at some point in the future. You still don't need any extra words - many people might be more likely to ask How long will you need the book for?, but including the preposition doesn't really affect the meaning. Commented Jan 5, 2017 at 19:48
• @FumbleFingers I think there's still a miscommunication here. Let's say t's 8 and I am in possession of the book for now, until an unknown amount of time will have passed when they will need the book and so I'll have to give it to them. Commented Jan 5, 2017 at 20:06
• I can imagine contexts where the speaker doesn't care when the book will become needed (only how long, after that point). If he really needs to know both, something like When and for how long will you need the book? would be suitable. I can't easily think of natural phrasing that avoids the need to use for in that case, but it's not necessary if he's only asking about the duration and not the time at which that duration starts. Commented Jan 5, 2017 at 21:38

Usually the pattern

how long until something

is used to ask the delay in something starting.

A - How long from now will you need (be needing?) the book?

B - How long will you need the book from now?

If the other person is getting the book now and you want to know when they will be finished with it:

When [will/do] you need the book until?

If the other person isn't getting the book now, but you want to know when they need to receive it:

When [will/do] you need the book [from me]?

C - How many hours will you need the book in?

D - In how many hours (In how long) will you need the book?

I believe C is technically correct, but I agree it doesn't roll off the tongue.

If you're asking how long (in hours) it will be until the other person needs to book (i.e. they don't have it yet), you could use:

How many hours until you need the book?

or simply as above:

When [will/do] you need the book [from me]?

If you're asking for the duration in hours that the person will need to keep the book, I would suggest:

How many hours will you need the book for?

E - How long till you will need the book?

This seems fine to me, although equally valid are:

How long until you will need the book? ("until" and "till" are interchangeable, the latter is less formal)

How long will it be [until/till] you will need the book?

F - How long will you need the book till?

If you're wanting to ask when the other person will be finished with the book, I think using "how long" and "till/until" together here creates a conflict. You either want something like:

How long will you need the book for?

or

When will you need the book [until/till]?

• Thanks. I just need to know how long it will be till they need the book. Like it's 8:00 now and I need to know in how many hours they will ask for the book to be given to them cause they will need it at that time. Their answer could be: 2 hours. Or : in 2 hours. So I know I have 2 more hours till I need to handing the book over to them. Commented Jan 5, 2017 at 20:02
• Then I think "When will you need the book?" or any of the equivalent examples I give above would be fine. If you want to imply that you expect it to be within a few hours (rather than several days or weeks), then you could be specific "How many hours until you need the book?". Commented Jan 5, 2017 at 20:06
• Yes. This is exactly what I was looking for. Thank you. Commented Jan 5, 2017 at 20:08
• No problem, glad it was helpful. Feel free to accept and upvote the answer if you found it useful in answering your question. Commented Jan 5, 2017 at 20:14