A stupid person who knows he is stupid is not stupid; a stupid person who thinks he is smart is the stupidest of all.
自知为愚者的愚者并不愚蠢；自以为聪明的愚者却是愚者中之愚者。
He sighed for the crafty, for the cunning, for the stupid, for the doltish, for the upright and sincere, and for the country bumpkins.
叹黠者、狡者、愚者、拙者、直谅者、乡愚者；
A fool may ask more questions in an hour than a wise man can answer in seven years
愚者所问,智者难答
It is foolish to live poorly for the sake of having a great deal of money when one dies.
愚者生时贫困，死时富有。
Sometimes a fool is able to give good advice to a person much wiser than himself because of some special knowledge he has.It implies that one should not ignore advice no matter from whom it comes.
愚者千虚，必有一得。
A fool's bolt is soon shot.
愚者易于智穷力竭。
Fools build houses and wise men live in them.
愚者造房，智才租房
The fool doth think he s wise, but the wise man knows himself to be a fool. --William Shakespeare
愚者自以为智，智者则自以为愚。——莎士比亚
Fools learn nothing from wise men, but wise men barn much from fools.
愚者不能从智者那里学到什么东西，但智者从愚者那里得益良多。
"The fool does think he is wise, But the wise man knows himself to be a fool"
愚者自以为聪明,智者则有自知之明
The wise know how to teach, the fool how to smite.
智者知道如何教导，愚者知道怎样破坏。
Wise men have their mouths in their hearts, fools their hearts in their mouths.
智者嘴在心里，愚者心在嘴里。
The fool doth think he is wise, but the wise man knows himself to be a fool.
[谚]愚者自以为聪明，智者则有自知之明。
"Wise man have their mouths in their hearts, fools have their hearts in their mouths"
智者嘴在心里,愚者心在嘴里
"A wise man thinks all that he says, a fool says all that he thinks"
智者思其所言,愚者言其所思
Wise men love truth, whereas fools shun it.
智者热爱真理，愚者回避真理
A wise man changes his mind, a fool never will .
智者随机应变，愚者墨守成规。
(informal) having or revealing stupidity.
（非正式）愚蠢或者显示出愚蠢。