It is a common rule of the English language.
Mutated plurals are irregular plurals (where you DON'T just add an "s"). Children geese hooves women
The great majority of nouns are made plural by simply adding -s to the end of the word:apple-applesboy-boyscoin-coinsWords ending in s, z, ch, sh, and x add -es to the end of the word to form the plural:boss-bosseswaltz-waltzesmatch-matchesdish-dishesbox-boxesThere are many other forms of plurals in English that don't use these forms; they're called irregular plurals. See the link below for the variations in forming plurals.
If the word you are making into a possessive ends in s because it is a plural, then you add an apostrophe after the s to make it possessive. In all other cases, including words which end in s for any reason other that because they are plurals, you add an apostrophe and the s.
If the word you are making into a possessive ends in s because it is a plural, then you add an apostrophe after the s to make it possessive. In all other cases, including words which end in s for any reason other that because they are plurals, you add an apostrophe and the s.
When forming plurals for singular words that end in an "s" sound, we usually add "-es" to the word to indicate pluralization. For example, "bus" becomes "buses" and "class" becomes "classes."
so you can make plurals
Yes, regular plural constructions just add an "s" to the end of the word. E.g. "Stools".
Alto (male) alta (female) - add 's' for plurals in each case.
The plural of colleague is colleagues. This follows the basic rule for forming most plurals: just add an "s".
The plural of receipt is receipts. This follows the general rule for forming plurals, which is simply to add an "s" at the end.
You usually add "-es. Many Latin-origin words ending in -us form plurals by changing -us to -i.
The possessive of all English plurals ending in -s is formed by adding an apostrophe after the final s: the Joneses' house. (Do not mistake singulars that end in -s, like Jones or Charles for plurals).