Here is an example The Royal Canadian Mounties ride on their mounts. If you could not differentiate you would not know who or what is riding what or who. The Royal Canadian mounts ride on their mounts would not work.
Most nouns add an "s". (This is what's really happening in the example above. The singular is Mountie.) Nouns that end in "s", "x" and "z" add "es". (But words that end in "us" drop the "us" and change to "i" like cactus>cacti.) Nouns that end in "y" change the "y" to an "i" and add "es". Some nouns have a totally different pluralization: mouse>mice, ox>oxen, datum>data. Some words borrowed from other languages use "i" for pluralization.
In American English, it is extremely rare for a plural word to end in a letter outside of "S".
Some plural nouns that end with 'os' are:avocadosbanjosbarriosbongosechosegosflamingosghettosgigoloshaloshobosJellokangaroolassologosnachospatiosphotospianospiccolosradiosrhinossolosstudiostacostattoostriosvideoszeroszoos
Some words that end in -s that are always plural are:accommodationsamendsarchivesbarracksbinocularsbowelsclothescommunicationscongratulationscontentscrossroadsforcepsgallowsglasses (vision aid)goodsheadquartersjeansmathematicsmeansnewspajamaspantsscissorsseriesshortsspeciesstairstongstrouserstweezers
singular form = ox, plural = oxen singular form = man, plural = men single = child, plural = children single = woman, plural = women
Some words end in -fe, e.g knife (that is in singular) but when you turn it to a plural you write knives.
borradores Words that end in consonants add -es to be made plural; words that end in vowels add -s.
Most plural words do.
what are the greek words end by 'on' in singular and change to 'a' in plural?
These words end in O and make the plural by adding ES. buffalo buffaloes domino dominoes echo echoes embargo embargoes hero heroes mosquito mosquitoes potato potatoes tomato tomatoes torpedo torpedoes veto vetoes
Two plural words ending in '-s':table > tableschair > chairs
The possessive of PLURAL nouns ending in -s is formed by adding a final apostrophe: girls'. Plurals that do not end in -s form the possessive by adding -'s: women's Because the already end in the letter "s" such as octopus
"Children", "Women" and "Fish" are plural words that do not end with an 's'. There are many more.