What is key?

What is key?

keys
1. The basic method of changing nouns from singular to plural is as follows:
① Add S. at the end of singular nouns, such as map → maps, boy → boys, horse → horses, table → tables
② For example: class → classes, box → boxes, hero → heroes, dish → dishes, bench → benches
[note]: for a few words ending with O, only s is added when the plural is changed, such as: photo → photos, piano → piano
③ A noun ending with a consonant letter Y, changes y to I, and then adds es. For example: family → families, city → cities, Party → parties
④ For nouns ending with f or Fe, change f or Fe to V and add es, such as: shelf → shields, wolf → wolves, life → lives, knife → knives
2. Irregular changes: man → men, woman → women, sheet → sheet, tooth → tea, fish → fish, child → children, ox → oxen, goose → geese
Generally, uncountable nouns do not have plural forms. When explaining their quantity, we should use relevant quantifying nouns, such as: a bag of rice → two bags of rice, a piece of paper → three pieces of paper, a bottle of milk → five bottles of milk