The most common rule for forming plural nouns is A. adding -es to the word. B. adding -s to the word. C. dropping the last letter and adding -ies. D. changing the y to i and adding -es.
B. The most common rule for forming plural nouns is by adding –s to the singular word which is the simplest among all rules. Examples are given below: 1. Boy (singular), add (s) to make it plural so it become: boys 2. Girl -> girls 3. Book -> books
