"Overalls" is a plural noun. Some articles of clothing, like overalls, have two parts and only have a plural form.
"Overalls" is a plural noun or plurale tantum (Latin for "plural only"). Some articles of clothing, like overalls, have two parts and only have a plural form.
Are your overalls clean?
Is your overall clean?
These nouns are grammatically plural, and cannot be used with the indefinite article "a" ("a" means a single thing). However, you can make them countable by introducing the phrases "a pair of overalls", "two pairs of overalls", "three pairs of overalls", etc.
How many pairs of overalls does she have?
She has five pairs of overalls.
Remember, the word "overall" (without "s") is an adjective or an adverb, not a noun.
The overall cost was $753,000. (adjective)
Overall, Olivia did a fairly good job. (adverb)
Plural nouns take a plural verb and a plural pronoun, so we say "those overalls are", not "this overalls is".
Your overalls are on the bed.
Your overalls is on the bed.
A partial list of articles of clothing that are also plural nouns can be found below:
