A plural noun is a word that indicates that there is more than one person, animal place, thing, or idea. When you talk about more than one of anything, you’re using plural nouns. When you write about more than one of anything, you usually use the same word, simply adding an s, es, or ies to the end.
Educando recomends that you explain that most nouns are regular but some are irregular because this rule does not apply to them, such as:
tooth / teeth
foot / feet
