Some grammar books divide nouns into 2 groups - proper nouns and common nouns . Proper nouns are nouns which begin with a capital letter because it is the name of a specific or particular person place or thing. If you see a word beginning with a capital letter in in the middle of a sentence, it is probably a proper noun . Most nouns are common nouns and do not begin with a capital letter.
Many nouns have a special plural form if there is more than one.
For example, we say one book but two books . Review this lesson as many times as you want, and when you are ready, take the pop quiz on this chapter.