Plural Countable nouns
Incorrect: He has written a lot of book.
Correct : He has written a lot of books.
Incorrect : He ate five mango at a time.
Correct : He ate five mangoes at a time.
Note: Regular plural endings of nouns are 's’ and 'es’. When you use a plural noun, you should not forget these endings. However, some nouns have irregular plurals. For example:
man -> men, Woman -> Women,
child -> children, ox --> oxen,
foot --> feet, tooth -> teeth,
goose --> geese, mouse -> mice etc.
