The usual way to form a plural is to add an -s, e.g. dogs, popes.
If the word ends in -ch, --s, -sh, -x, -z, then add -es, e.g. branches, masses, bushes, boxes, chintzes.
Most words that end in -f or -fe change the ending to -ves (e.g. wives, calves), although there are exceptions (e.g. beliefs, chiefs, dwarfs, gulfs, proofs, roofs).
For words that end in a vowel + y, add -s, e.g. days, boys.
If a word ends in a consonant + y, change the -y to -ies, e.g. babies, spies.
Words that end in -o normally just add -s, but there is a group of words that add -oes: these include buffaloes, dominoes, echoes,
goes, grottoes, haloes, heroes, mangoes, mosquitoes, potatoes, tomatoes, tornadoes, torpedoes, vetoes, and volcanoes.
