know better

Idioms

Be able to recognize something as wrong or not possible, as in Mary should know better than to leave her child alone in the house, or Try to get in without a ticket? You know better than that. [c. 1700]

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

This keeps happening, even to people who should know better.

From Barron's • Apr. 29, 2026

Members of law enforcement view themselves as role models for youth; youth often know better, understanding that police treatment predicts how safe they are—or are not.

From Slate • Apr. 27, 2026

No matter how much he practices at any other course, however, there won’t a major venue he’ll ever know better than Augusta.

From The Wall Street Journal • Apr. 13, 2026

In talking with them, I realize that a true friend would know better than to act the way I did and for that I need to be a better friend.

From Los Angeles Times • Mar. 18, 2026

I will share this, though I know better about such things.

From "The Detective's Assistant" by Kate Hannigan

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023