The word(s) "unless" appears 31 time(s) in 31 verse(s) in Quran in Mohsin Khan translation.

(21) And come not near to unlawful sex. Verily, it is a Fahishah (i.e. anything that transgresses its limits: a great sin), and an evil way (that leads one to Hell unless Allah forgives him).

(22) "I will surely punish him with a severe torment, or slaughter him, unless he brings me a clear reason."

(23) And never will your Lord destroy the towns (populations) until He sends to their mother town a Messenger reciting to them Our Verses. And never would We destroy the towns unless the people thereof are Zalimun (polytheists, wrong-doers, disbelievers in the Oneness of Allah, oppressors and tyrants).

(24) And argue not with the people of the Scripture (Jews and Christians), unless it be in (a way) that is better (with good words and in good manner, inviting them to Islamic Monotheism with His Verses), except with such of them as do wrong; and say (to them): "We believe in that which has been revealed to us and revealed to you; our Ilah (God) and your Ilah (God) is One (i.e. Allah), and to Him we have submitted (as Muslims)."

(25) O you who believe! Enter not the Prophet's houses, unless permission is given to you for a meal, (and then) not (so early as) to wait for its preparation. But when you are invited, enter, and when you have taken your meal, disperse without sitting for a talk. Verily, such (behaviour) annoys the Prophet, and he is shy of (asking) you (to go); but Allah is not shy of (telling you) the truth. And when you ask (his wives) for anything you want, ask them from behind a screen: that is purer for your hearts and for their hearts. And it is not (right) for you that you should annoy Allah's Messenger, nor that you should ever marry his wives after him (his death). Verily, with Allah that shall be an enormity.

(26) Whosoever desires honour, (power and glory), then to Allah belong all honour, power and glory [and one can get honour, power and glory only by obeying and worshipping Allah (Alone)]. To Him ascend (all) the goodly words, and the righteous deeds exalt it (i.e. the goodly words are not accepted by Allah unless and until they are followed by good deeds), but those who plot evils, theirs will be severe torment. And the plotting of such will perish.

(27) unless it be a mercy from Us, and as an enjoyment for a while.

(28) It is not given to any human being that Allah should speak to him unless (it be) by Revelation, or from behind a veil, or (that) He sends a Messenger to reveal what He wills by His Leave. Verily, He is Most High, Most Wise.

(29) And they will not receive admonition unless Allah wills; He (Allah) is the One, deserving that mankind should be afraid of, and should be dutiful to Him, and should not take any Ilah (god) along with Him, and He is the One Who forgives (sins).

(30) But you cannot will, unless Allah wills. Verily, Allah is Ever All-Knowing, All-Wise.