Regarding the problem of complex number +(e)s, yoyo should also be generated according to the deformation method. The plural of yoyoyos is yoyoyos, so it is not appropriate to force +es here. Those ending in O, S, X, ch, sh, add es at the end of the word, but some loanwords or abbreviations ending in O only add S. If there is a vowel before the letter O, only add S. Changing yoyo into plural means adding es, yoyoes.

The ending o is followed by a vowel letter (a, e, I, o, u) or a semi-vowel letter (y, w). Like radio, zuz, embryo. This rule can already be seen that yoyo can only be+S.

Extended data:

When singular nouns end with s, z, x, sh and soft ch (suffix consonants are /s, z,? ,? /and so on. ) add -es (read /iz/), such as: box-box, peach-peach. (o Sometimes, but es is pronounced as /z/ as hero-heroes) Exception: stomach-stomach (pronounced as /k/ due to ch).

Irregular changes, such as cow-cow, child-child, man-man, mouse-mouse, lice.

Do not change, such as: deer-deer, sheep-sheep and collective noun people-people, Han-Han.

Add s in the middle of conjunctions, such as hanger _ on-hanger _ on, maid_of_honor-maids_of_honor.

Countable nouns end with the consonant letter +y, and y and ies are removed, such as hobby- hobby, factory- factory.

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