Some nouns, like "glasses", consist of two parts and only have a plural form.
When talking about an object that people wear in front of their eyes to help them see better, we say "glasses are" (not "glasses is"). Some nouns, like "glasses", consist of two parts and only have a plural form.
Your glasses are on my desk.
Your glasses is on my desk.
Follow the same strategy with other verbs, such as have, fit, look, etc.
Make sure your glasses fit properly. (not "fits properly.")
Plural nouns, like "glasses", cannot be used with the article "a"; however, you can use the expression "a pair of glasses". Since "pair" is a collective noun that requires a singular verb, we use "is" with it.
There is a pair of glasses in your room. (not "There are...")
And remember, we always use a plural pronoun or determiner (these, they, those, them, etc.) with plural nouns.
Those glasses look great! Where did you buy them?
This is a partial list of objects where two things are joined together. Being plural, they take "are" as well:
