Chinese idiom · 成语
空口无凭
Meaning
Empty words lack proof; promises without evidence.
Character by character
Origin and story
Colloquial literary usageAn exact example appears in chapter 27 of Li Baojia's Guanchang xianxing ji: a speaker says he would not dare bring his senior a statement unsupported by evidence. The same practical distinction appears in the older variant 口说无凭, used in Chuke pai'an jingqi and Honglou meng when spoken claims are contrasted with something that can substantiate them.
The expression is a compact everyday judgment rather than a tale about one uniquely deceptive person. 空口 means bare words; 凭 is a basis or proof. It does not necessarily accuse a speaker of lying, but asks for support that others can inspect rather than relying on an assertion alone.
Sources and further reading
In everyday life
你说已经付过钱，可空口无凭，能不能把转账记录给我看看？
You say you've already paid, but words alone aren't proof—could you show me the transfer record?
Can sound skeptical or confrontational; asks for evidence rather than mere reassurance.