Following words need special attention before making their plurals
Child-Children
person-people
foot-feet
mouse-mice
tooth-teeth
man-men
woman-women
ox-oxen
goose-geese
Now look at the following words as they have same identical singular and plural form
aircraft-aircraft
fish-fish
headquaters-headquaters
sheep-sheep
species-species
deer-deer
Some nouns exists only in plural form
cattle
scissors
trousers
tweezers
congratulations
pyjamas
Note- The uncountable noun will take only singular form which will be discussed in the next post
