The word(s) "understand" appears 127 time(s) in 127 verse(s) in Quran in Abdullah Yusuf Ali translation.

(11) To those weak of understanding Make not over your property, which Allah hath made a means of support for you, but feed and clothe them therewith, and speak to them words of kindness and justice.

(12) O ye who believe! Approach not prayers with a mind befogged, until ye can understand all that ye say,- nor in a state of ceremonial impurity (Except when travelling on the road), until after washing your whole body. If ye are ill, or on a journey, or one of you cometh from offices of nature, or ye have been in contact with women, and ye find no water, then take for yourselves clean sand or earth, and rub therewith your faces and hands. For Allah doth blot out sins and forgive again and again.

(13) "Wherever ye are, death will find you out, even if ye are in towers built up strong and high!" If some good befalls them, they say, "This is from Allah"; but if evil, they say, "This is from thee" (O Prophet). Say: "All things are from Allah." But what hath come to these people, that they fail to understand a single fact?

(14) Ye are never able to be fair and just as between women, even if it is your ardent desire: But turn not away (from a woman) altogether, so as to leave her (as it were) hanging (in the air). If ye come to a friendly understanding, and practise self-restraint, Allah is Oft-forgiving, Most Merciful.

(15) When ye proclaim your call to prayer they take it (but) as mockery and sport; that is because they are a people without understanding.

(16) Say: "Not equal are things that are bad and things that are good, even though the abundance of the bad may dazzle thee; so fear Allah, O ye that understand; that (so) ye may prosper."

(17) Of them there are some who (pretend to) listen to thee; but We have thrown veils on their hearts, So they understand it not, and deafness in their ears; if they saw every one of the signs, not they will believe in them; in so much that when they come to thee, they (but) dispute with thee; the Unbelievers say: "These are nothing but tales of the ancients."

(18) What is the life of this world but play and amusement? But best is the home in the hereafter, for those who are righteous. Will ye not then understand?

(19) They say: "Why is not a sign sent down to him from his Lord?" Say: "Allah hath certainly power to send down a sign: but most of them understand not.

(20) Say: "He hath power to send calamities on you, from above and below, or to cover you with confusion in party strife, giving you a taste of mutual vengeance - each from the other." See how We explain the signs by various (symbols); that they may understand.