A small black bag

The rule, as people use it

An adjective describes a noun: small, cheap, tired, quiet. In English it goes in one of two places. Before the noun: "a quiet street". Or after a verb like be, look, feel, sound, smell and taste: "The street is quiet." "You look tired." "This soup tastes great."

An adjective never changes. It has no plural and no he or she form. So it's "two big houses", never "two bigs houses", and "she's tall" for everyone. Many languages add an ending here. English doesn't, and that makes it one less thing to think about.

When you stack two adjectives, your opinion usually comes first, then size, age and color: "a lovely old hotel", "a small black bag". You don't need a chart for this. Say both orders out loud and one will sound strange.

The slip learners make most is with -ed and -ing. "Bored" is how you feel. "Boring" is the thing that makes you feel that way. "I'm bored" means the movie is slow. "I'm boring" means you are the problem. The same goes for tired and tiring, interested and interesting, excited and exciting.