The
plurals of words ending in -o are formed by either adding -s or by adding
-es. The plurals of many words can be formed
either way. To determine
whether a particular word ends in -s or -es (or if the word can be spelled either
way), check your the list below and if you have to check your
dictionary. There are two helpful rules:
a. All words that end in a vowel plus -o (-ao, -eo, -io, -oo, -uo)
have plurals that end in just -s:
- stereo--stereos
- studio--studios
- duo--duos
b. All musical terms ending in -o have plurals ending in just -s.
- piano--pianos
- cello--cellos (I have been told that the plural for cello is actually, celli)
- solo--solos
c. Plural forms of words ending in -o: