Badly behaved (adjective)

[Phillingual]

English Idioms and Expressions, Elementary Level

ESL/EFL Test #6 "Out of Control", question 1

If you don't tell the children the difference between right and wrong, they will soon be out of control.

(a) well behaved
(b) badly behaved
(c) suddenly behaved
(d) quickly behaved

English Idioms and Expressions, Elementary Level

ESL/EFL Test #6 "Out of Control", answer 1

If you don't tell the children the difference between right and wrong, they will soon be badly behaved.

Correct answer: (b) badly behaved

Your answer was: correct
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Hi! Teachers,
I'd like to ask why be behaved is used here instead of behave. Is it because the verb imply the meaning of behave yourself? But behave can also be used as a vi., right?

Phillingual

[Canadian45]

You have to use behaved because you need an adjective. Behave can only function as a verb.

The children will soon be badly behaved. (adjective)
The children will soon behave badly. (simple tense verb)
The children will soon be behaving badly. (future progressive tense verb)