[Grammar] Plural of hair

[shavetang]

what is the plural of hair? are these sentences correct? 1)that is a hair. 2)those are hairs.

 

[emsr2d2]

What is the plural of hair? Are these sentences correct?

1) That is a hair.
2) Those are hairs.

Note my corrections to your post and to your title. Thread titles should include some or all of the words you are querying.

Both your sentences are grammatically correct. However, "hair" can be both countable and uncountable. As a countable noun, the plural is "hairs". If you are talking about all the "hairs" on your head, it's just your "hair".

I can see some red hairs on the sofa. Do you have a red dog?
I can see that you have red hair. Is it natural or do you dye it?