"What do you like to do?"
Translation:Was machst du gern?
"machst" corresponds to the meaning of "to do". In German there is no (common) direct translation of "like to + infinitive", but we use a finite verb and the adverb "gern": I like to swim -> Ich schwimme gern (lit. "I swim gladly"). The literal translation of "What do you like to do" would be "Was magst du zu tun?", which might be understood, but isn't really proper German. It's also more like a question about what you would like to do right now, while the version with "gern" is a general statement.