单复同形 如：
deer,sheep,fish,cattle, deer, salmon, Chinese,Japanese
较特殊的有:
child---children
foot---feet
tooth---teeth
mouse---mice
man---men
woman---women
thief thieves
shelf shelves
leaf leaves
calf calves
half halves
wolf wolves
wife wives
life lives
以sh,ch,s或x结尾的话,那就要在单数的后面加上es
lash lashes 鞭子
push pushes
branch branches
match matches
coach coaches
gas gases
ass asses
class classes
box boxes
fox foxes
如果名词结尾是一个子音(consonant,就是除了a,e,i,o,u之外的字母)加一个y, 那就要将y换成i,再加上es
baby babies
family families
pony ponies
city cities
country countries
如果名词结尾是一个母音(vowel,就是a,e,i,o,u)加一个y,那只要在单数词后加一个s就成了
play plays
way ways
valley valleys
donkey donkeys
toy toys
boy boys
guy guys