Which sentence is correct:
You are acting ridiculous.
or
You are acting ridiculously.
I thought that the first sentence, which uses ridiculous, is correct. In this instance, acting ridiculous appears to be a phrase, perhaps a gerund phrase, which acts as a complement to the linking verb be. Accordingly, you would use the adjective ridiculous and not the adverb ridiculously.
I called numerous grammar hotlines. All except for one said that the second sentence, which uses the adverb ridiculously, is correct. These people are convinced that act is the main verb and can’t even entertain the possibility that be is the main verb. They all seemed lacking in grammatical terminology. One woman finally agreed with me, but I think that she only did so because she felt bullied by me and didn’t want to deal with me anymore.
The one grammar hotline, which seemed to have some clue about English, offered me this advice, which seemed the most viable: Both sentences are correct. The first describes the person, and the second describes the behavior of the person.
I am still not completely sure what the answer is, though I am pretty sure that there are few, if any, grammarians alive.
