Thank you Grammar Geek for your help.
@To All:
I have another question and I don't want to post another topic so I will ask here, please help me out.
How do you know when to use and when not to use the apostrophe " 's " to specify an object? And how do you use a noun to specify another noun?

For example, I know we should use "enemy bases" rather than "enemy's bases", or "cowboy pants" rather than "cowboys' pants". Can you state a general rule here?

I also notice that when you use nouns as modifiers for other nouns you should put them in their singular forms. Is it true?

Have a good day, people!

Best Regards,
Please do start a new thread with a new question. I have split this one for you.

When you use a noun as an adjective, you don't use the possessive. What TYPE of a hat? A cowboy hat. If you are answering "Whose?" instead of "What type?" then use the possessive. That cowboy's hat has a bullet hole through the crown.

Yes, generally the noun is in the singuar: book store, shoe shop, car dealer. The exception that comes readily to mind is sports. Sports car, sports arena.
To All:
Can you find other instances of modifier nouns in the plural besides "sports"?
May be "news" ?

P/S: I didn't start a new thread because I feel that this question is closely connected to the above question, but if you do need me to create a new topic, I will.

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PrinnySquadCan you find other instances of modifier nouns in the plural besides "sports"?
It seems to me that there are very few. I came across "people mover" once -- that sort of "horizontal escalator" found at airports.
Two more which spring to mind are "arms dealer" and "antiquities dealer".

In the case of "arms dealer", maybe it's because an "arm dealer" would be something else entirely. Emotion: smile
Yes, and a news dealer and a New Dealer are quite different also.

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What of 'value' and 'values'? 'Value' in the sense of a thing of importance to a person, can only be made sensible when it is associated with another concept. Is there a name for this kind of noun?
Hello, Julian—and welcome to English Forums.

Your question does not seem to apply to the discussion in this thread, but to be frank, I am not sure what your concern about 'value(s )' is, since 'value' in the sense of 'be of value to (someone)' certainly makes sense, irrespective of whether the thing of value is intelligence, a driver's license, or a beautiful girlfriend.