略知

He has a superficial knowledge of this subject.

他对这门学科略知皮毛。

Edward had only a smattering of Welsh.

爱德华对威尔士语只略知一二。

You need at least a nodding acquaintance with the rules of chess to understand the book.

你得对国际象棋规则略知一二才看懂这本书。