Nobody answered my question.
You'll get faster answers here if you don't say things like "lol" and "wanna" and don't start sentences with small letters. I know your question is serious, but when you use sloppy English, it makes it seem as though you're not taking your studies seriously. We're glad to help improve your English, but only when we know you're trying.
Your example,
by now, is an idiom and cannot be translated word-for-word.
Adverbs go with verbs. So an adverb can go after a preposition if there is a verb for the adverb to go with. Example:
-
After quickly reading the email, he decided to delete it.
Do you have other examples you're wondering about?