in grammer where puts the s. or es in numbers plz expain ;for example : car ,cars /mango -mangoes

S is use in common plural except few exception.
es, word ending with SS,  CH, SH, X, TH, O
SS - classes
Ch - blanches, churches, branches
SH - brushes
X - boxes
O - mangoes, tomatoes
Some irregular plurals - children, teeth, mice, etc.
Same plural - deer, fish, dozen

S with O - Bamboo, Radio, video, stereo, piano, igloo, Eskimo, photo