The regular change of nouns into plural.

1. Add s in general.

2. add es at the end of s, x, sh and ch, which is pronounced as /iz/.

3. End with consonant +y, change y to I, add es, and pronounce it as /iz/.

4. ending with the consonant letter +o, there is life plus es; Stupid plus S.

5. end with f and fe, and when it reaches f, fe becomes ves.

Radio and piano all end with O, so add S directly.

In addition, except for two people (blacks and heroes) and two dishes (tomatoes and potatoes) plus es, other words ending in O generally add S. Memory formula: blacks and heroes love tomatoes and potatoes.

An inanimate noun ending in -o plus-s. Such as:

Photo (photo); Video (video); Radio, kg; Zoo; Piano (piano) ...

Some nouns irregularly form plural forms.

Such as: male-male (male), female-female (female); Mice-mice-children; Teeth-teeth (teeth); Foot-foot, etc.

Some nouns have the same singular and plural.

Such as: sheep-sheep-deer; People-people, and so on.