The untold halves of common Chinese sayings

Xiehouyu (歇後語) is a two-part idiom in Chinese language which acts like a riddle or a game of humour between the speaker and the listener. The first part of Xiehouyu is usually the riddle part which gives the hint for the listener to guess the second part. The second part is omitted in a conversation (often involves a pun related to the first part) but the listener is usually able to guess it right and probably would smile because of the humour involved.

Examples of Xiehouyu are :

「老公撥扇」： 淒涼 (與妻涼諧音) 。
「白鱔上沙灘」： 唔死一身潺 。
「火燒旗杆」： 長嘆 (與長炭諧音) 。
「秀才遇著兵」： 有理說不清。

An analogy in English might be “imiate an amoeba (and split)”.