It is less so than it should be.
Is the sentence above grammatical? And if so, is "so" in that sentence an adjective?
Yes, it's grammatical. Even though "so" may seem to substitute for a previously-mentioned adjective, it nevertheless feels to me like an adverb.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
Yes, it's grammatical. Even though "so" may seem to substitute for a previously-mentioned adjective, it nevertheless feels to me like an adverb.