Mouth civility costs little but is worth less.

Understand the thought

Meaning in plain English

Polite words are easy to offer, but they have little value when unsupported by considerate conduct. Look beyond courteous speech to how someone actually treats others.

What the words are saying

The mouth supplies civility through speech, while the saying asks what that civility is worth. It challenges a performance of good manners that costs the speaker little and leaves another person’s situation unchanged. A courteous promise to help may be hollow if it is repeatedly followed by neglect. This does not make politeness useless: respectful language can itself reduce friction and acknowledge someone. The sharper point is about substitution, when words are offered in place of the care or action the occasion requires. Judge the relationship between the statement and subsequent conduct, rather than dismissing every verbal courtesy.

Everyday example

A coordinator repeatedly thanks volunteers for their patience but ignores their requests for the missing schedule; a colleague asks for the timetable as well as the thanks.

When to use it

Use it when courteous language repeatedly substitutes for needed action or care.

Agent-assisted editorial interpretation. This explains the words; it does not by itself verify their author or earliest origin.