Singular nouns name one person, place, thing, or idea.
One dock had rows of ships in its harbor. singular noun
Plural nouns are usually formed by adding -s or -es. They name more than one person, place, thing, or idea. When a singular noun ends in s-sh-ch-or x, add es to make the plural form.
The three cats climbed to the top of the oak tree.
The postman delivered four boxes to the house.