What part of speech is the word "sleep" in this sentence?
You should have eight hours of sleep each night.
What part of speech is the word "sleep" in this sentence?
You should have eight hours of sleep each night.
WS2 is correct - it is an abstract noun.
sleep noun
- dormancy or inactivity
Source: Dictionary.com
The reason why "sleep" (in this context) is abstract and not concrete is because you can't physically touch it.
To answer such a question, you have to start with the whole structure and work your way down to the smaller parts, until you get to "sleep". The subject is "you", the object of "have" is the noun phrase "eight hours of sleep". Within that noun phrase, the complement of the noun "hours" is the prepositional phrase "of sleep". I'll leave the rest to you.