Are is for multiples. Is is for singular That apple IS red Those apples ARE red That man is angry Those men are angry Where is it Where are they "Are" can be used other wata., though, and it's a bit trickier. What is the specific context source of the question?

The word "Is" is used when a subject is singular, and "Are" is used when a subject is plural.

"Are" can be used for plural subjects AND second person singular subjects. You can't say "You is", even though "you" is singular. "Is" is only used when the subject is singular AND in the third person e.g. "It is...", "The dog is...". "Am" is used when the subject is first person singular ie. you'd say "I am...", and never "I is...".