Caps Lock

[jack]

Are these correct? What do they mean?
1. I need a Capitals Lock key for my keyboard. (Is 'capitals' an adjective? How come this is correct? I thought adjectives didn't take -s or -ed ?)
2. I need a Capital Lock key for my keyboard.
3. I need a Cars Lock key for my car. (If this is incorrect, why? #1 is correct?)
4. I need a Car Lock key for my car.

Are these correct? What do they mean?
5. I thought adjectives didn't take -s or -ed ?
6. I thought adjectives don't take -s or -ed ? (If this is incorrect, why? I hear people use 'don't' all the time?)

Thanks.

[Tdol]

I need a car lock. (1 lock per car)

We say Caps Lock or Capitals Lock as a short form of Captial Letter- we often use it as a plural, so we keep it in the plural- write the heading in capital letter/in capitals. It is a noun and when placed before Lock, it is a noun functioning as a kind of adjective. These are normally used in the singular, but can be plural if the plural form is the form most commonly used.

[jack]

1. Capitals Letters. (This is wrong right?)

And this is right:
2. Capitals Lock.
Because:

These are normally used in the singular, but can be plural if the plural form is the form most commonly used.

3. It is a noun functioning as a kind of (determiner) adjective. (How come you didn't use a determiner here? Or does this sentence mean 'adjective' in general? If 'adjective' is in general, is it a non-count noun then? Since you don't have a determiner there?)

Eg. :
4. It is a noun functioning as a kind of adjectives.
5. It is a noun functioning as a kind of an adjectives.
What do #4 and #5 mean?

Thanks.

[Tdol]

1- yes
2- yes
3- adjective is a count noun- but there is no need for a determiner- we don't usually have one after 'a kind of'
4&5 are wrong
;-0