Hello, As a native speaker, I'm gonna answer your question. These 4 sentences are all correct. losing polite form そうじゃありません →そうでない 「〜そう」expresses predictions, 「でない」expresses negative judgements. そうもありません→そうもない＝そうでもない 「〜そう」expresses predictions, 「でない」expresses negative judgements.「も」emphasizes negative judgements ＊I add 「で」because it is just dropped out (elision) and it is easy to clarify the difference. Also it doesn't matter which verb or adjective come before そうもありません、そうじゃありません。 Have a good day!