The major division of English nouns is into "countable " and "uncountable".

Countable nouns are easy to recognize. They are things that we can count. For example: "pen". We can count pens. We can have one, two, three or more pens. Here are some more countable nouns:

  • dog, cat, animal, man, person
  • bottle, box, litre
  • coin, note, dollar
  • cup, plate, fork
  • table, chair, suitcase, bag

Countable nouns can be singular or plural:

  • My¬† dog is¬†playing.
  • My¬† dogs are¬†hungry.

We can use the indefinite article a/an  with countable nouns:

  • A ¬†dog is¬†an¬†animal.
Countable nouns are also called "count nouns".

When a countable noun is singular, we must use a word like a/the/my/this  with it:

  • I want¬†an ¬†orange. (not¬† I want orange.)
  • Where is¬†my ¬†bottle? (not¬† Where is bottle?)

When a countable noun is plural, we can use it alone:

  • I like oranges.
  • Bottles can break.

We can use some and any  with countable nouns:

  • I've got¬†some¬†dollars.
  • Have you got¬†any¬†pens?

We can use a few and many  with countable nouns:

  • I've got¬†a few¬†dollars.
  • I haven't got¬†many¬†pens.
"People" is countable. "People" is the plural of "person". We can count people:
There is one person here.
There are three people here.

sources : Original Link