With phrasal verbs (a verb + preposition that creates a new unique meaning) you can often split the verb and the preposition. For example:
I looked up the word in the dictionary.
I looked the word up in the dictionary.
I'm sure there are some phrasal verbs that cannot be split, but I can't think of any at the moment, since most of the time you can. As for your question about adverbs, you'll have to give an example for me to understand your question.