A noun is a word for something in the world. It can describe a person (teacher), a thing (desk), a place (school), a time (year), a feeling (fear), an action (reply) or an event (lesson).
ORDINARY [S] girl [P] girls
GENITIVE [S] girl's [P] girls'
NOTICE:The pronunciation of girls, girl's and girls' is exactly the same.
PROPER NOUNS (Lesson 48) are names.
EXAMPLES: John, Paris
MASS NOUNS (Lesson 47) have only one form.
EXAMPLES: time, water
In every noun phrase, one noun (or pronoun) is the most important word. The other words 'belong' to it and give more information about it. You can learn about these other words in lessons 51-60.