看情况,如果turn up 后面没有宾语,意思是“出现”,up是副词,如He hasn't turned up yet .
但如果是turn up the radio/gas/Tv 等,后面接宾语了,则是介词,意思是“开大.”
jump 也一样,jump over the fence 跳过篱笆,宾语是fence ,那么over 就是介词.