Fill in the blank with the plural form of the nouns given in the bracket.
Our _________ played happily in the park. (CHILD)

The correct answer is: Children

Most singular nouns are made plural by simply putting an -s at the end. There are many different rules regarding pluralization depending on what letter a noun ends in. Irregular nouns do not follow plural noun rules. 'Our children played happily in the park', here the plural form of the noun child is children, and it is irregular noun which does not follow plural noun rules.