There are not concrete rules about using prepositions with verbs. We must memorize them. But sometimes we can guess meaning. For example, i had discovered that most verbs with "up" express movement to a higher place. to drink up or to eat up - means that i already drank and ate. also clear up means "stop raining". but definition of mix up is confuse and again appears difference. But difference is not very hard to guess. In addition i want to say it is not so difficult to learn common phrasal verbs. They are being used everywhere and if we meet them frequently we''ll memorize them necessarily. But for this we need time.

phrasal verbs are just common English, you should speak wtih a native to understand them more.

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