1. Plural-Only Nouns Some nouns only have a plural form, ending with s or without.The police are looking for the robbers.I like these pants / jeans / shorts.Use either scissors or nail clippers.Binoculars are stronger than any glasses. Other nouns ending with s only have a plural form only with certain meanings.customs (at the airport, not practices), guts (courage, not intestines)
quarters (lodgings, not 1/4s), clothes (garments, not fabrics)
goods (merchandise, not the opposite of bad), arms (weapons, not limb)
2. Singular Nouns with an S EndingPay attention!
 Some nouns end with s but are usually singular. They take a singular verb with an s ending in the Present Simple.
Diseases: measles, rabies.
Fields of study and occupation: economics, ethics, linguistics, politics, physics, gymnastics.
Games: dominoes, darts, cards
I study mathematics, which is very difficult. Dominoes is my favorite pastime.
• Some nouns have an identical form for singular and plural that both end with s.
Barracks, means, headquarters, crossroads,
a TV series – many TV series,Money is a means to an end.Newspapers and TV are means of mass-communication.There is one species of humans but many species of cats.3. Plural Nouns from Other LanguagesAs English has constantly borrowed words from other languages throughout its history, there are many nouns with plural endings taken from the source language. Some of these, notably Latin and classical Greek nouns, have been anglicized and may also have an English plural s ending.
Others have both forms, where the original is used in formal language or by specialists, while the anglicized is for more common use. Some of these are now almost only known or used in the plural form, which is treated as singular for subject-verb agreement (third person verb with s in the Present Simple). In the table below, the more common forms are underlined.