not have a clue/have no clue idiom informal
B2 毫无头绪；毫不理解；一无所知
to be completely unable to guess, understand, or deal with something
"Who invented algebra?" "I don't have a clue." “代数是谁发明的？”“我压根儿不知道。”
Don't ask your father which key to press - he hasn't got a clue about computers. 别问你父亲该按哪个键——他对计算机一窍不通。