This is a simple worksheet that practises a basic grammar rule: the plural of nouns ending in y. 

ESL students of English need to practise this rule time and again because it can't be understood intuitively. They need to learn this rule in order to form these plurals correctly.

The worksheet is simple, self-explanatory, and can also be used as an individual intervention for those students who don't form the plural for nouns ending in y correctly in their own texts.