I believe "forbidden" is an adjective. Your verb is "is". It IS forbidden to do that.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
AnonymousIs this correct grammar?It's correct.
AnonymousIs forbidden a verb or adjective?It's a tossup. I'd call it a verb.
ku1980roseOn the other hand, if you say, "I forbid you to do that" then "forbid" is being used as a transitive verb.True enough.
ku1980rose"Is" is a form of the verb, "to be". It is the simple present form of the verb.True again.