*Pair Nouns are the things which are made of two parts.The two parts are the same as follows:
glasses jeans shorts scissors trousers pyjamas pants
*A pair noun is always plural so it takes a plural verb:
EX:My jeans are black.Not my jeans is black.
EX:These scissors are sharp.
*A,an and numbers aren't used with pair nouns.But we use a pair of.
EX:I would like to buy a pair of jeans.
*If I want to buy more than one,I use numbers before pairs:
EX:I want to buy three pairs of scissors.
EX:My brother bought four pairs of glasses.
*Note that four glasses is correct when we mean a container of water.
EX:I drank four glasses of water.
*The collective nouns are a group of people ,animals, or things.They take either a singular or a plural verb.They are as follows:
army club class company family government team staff etc... .
EX:The government has made a lot of bad decisions.
EX:The government have made a lot of bad decisions.
EX:My family are rich.Or is rich.
EX:This team is co-operative.Or are co-operative.
*There are some nouns which have a plural meaning and take a plural verb:
EX:The police have arrested the thieves.
EX:The cattle are eating on the farm.
EX:People are sad.