Twenty hours' sleep. / Twenty hour sleep.

[sb70012]

Hi,
In this thread one nonnative English speaker has asked a question about:

1. Twenty hours' sleep.
2. Twenty hour sleep.

Tdol has said that number 1 is correct. But something confuses me. I say that 2 is correct. Because Hour can not possess Sleep. The word "hour" just modifies the word "sleep"

Look at my example:

We say "Two room house" not "Two rooms' house" or not "Two rooms house"

You see my confusion now? Would you please be kind enough to clarify it to me?

Thank you so much

 

[MikeNewYork]

Hi,
In this thread one nonnative English speaker has asked a question about:

1. Twenty hours' sleep.
2. Twenty hour sleep.

Tdol has said that number 1 is correct. But something confuses me. I say that 2 is correct. Because Hour can not possess Sleep. The word "hour" just modifies the word "sleep"

Look at my example:

We say "Two room house" not "Two rooms' house" or not "Two rooms house"

You see my confusion now? Would you please be kind enough to clarify it to me?

Thank you so much

"Apostrophe s" is not only used for possession. TDOL's answer was correct. We often use the "apostrophe s" with time references.

a month's salary
New Year's Day
a day's rest

We do not do that with "room". There should be a hyphen between "two" and "room" when it is used as an adjective.

 

[sb70012]

Thank you for answering.
Would you please be kind enough to tell me that in what context "twenty-hour sleep" and "twenty hours sleep" can work?

 

[emsr2d2]

I had a twenty-hour sleep.
I had twenty hours' ​sleep.

 

[sb70012]

I had a twenty-hour sleep.
I had twenty hours' ​sleep.

Thank you so much. Do they have the same meanings?

 

[MikeNewYork]

Thank you so much. Do they have the same meanings?

Yes. But it is very long.

 

[emsr2d2]

Thank you so much. Do they have the same meanings?

No, they do not necessarily mean the same. The first suggests that it was an unbroken period of sleep which lasted for twenty hours. I went to bed at 9pm and woke up at 5pm the next day. The second could be a total amount of sleep spread over an unspecified number of days/nights.

Q: How much sleep did you have last week?
A: I had twenty hours' sleep. I slept for two hours each night from Monday to Friday, but on Saturday and Sunday I slept for five hours each night.

 

[sb70012]

I had a twenty-hour sleep.
I had twenty hours' ​sleep.

Thanks for answering.
Is "I had twenty hours sleep" incorrect?

 

[emsr2d2]

Thanks for answering.
Is "I had twenty hours sleep" incorrect?

Yes, it is incorrect. If it had been correct, I would have used it.