This is an example of a genitive form known as an objective genitive, rather than an example of simple possession (if it were simple possession one might legitimately question whether an hour can actually possess sleep). We are really talking about 'a sleep of an hour', i.e. sleeping for an hour.
English only has few ways of indicating the genitive case, one of which is the apostrophe-s form. Thus "An hour's sleep" is correct.
It means: I generally sleep five hours
You should sleep 9 hours
they sleep for 10 hours a day they sleep for 10 hours a day
"asleep" would be correct grammar, not "sleep"
How many hours does it sleep
first 2 hours of sleep light sleep middle hours 3- 5 deep sleep 1-3 hours light sleep
they need about 6 hours of sleep
Sleep apnoea in British English or sleep apneaAmerican English.
Everybody is different once it comes to sleep. Most researchers agreed upon 8 hours asleep at night time is healthy as long as the quality of sleep is good. Addenda Absolutely correct. Some people need more sleep than others. Anywhere between 2 and 10 hours. As an adult 6 to 8 is normal but not a requirement.
Its compulsary for a teen ager to sleep 8 hours..
Elephants sleep for 2 hours
My doctor has told me that tweens need 9 hours of sleep a night! A Sleep Doctor should tell you to sleep 10 hours of sleep not 9 hours. Now Adult can sleep up to 6 hours, there bodys don't need that much sleep:)