The word(s) "plain" appears 49 time(s) in 49 verse(s) in Quran in Muhammad Habib Shakir translation.

(31) And if you reject (the truth), nations before you did indeed reject (the truth); and nothing is incumbent on the apostle but a plain delivering (of the message).

(32) And they say: Why are not signs sent down upon him from his Lord? Say: The signs are only with Allah, and I am only a plain warner.

(33) But when We decreed death for him, naught showed them his death but a creature of the earth that ate away his staff; and when it fell down, the jinn came to know plainly that if they had known the unseen, they would not have tarried in abasing torment.

(34) And We have not taught him poetry, nor is it meet for him; it is nothing but a reminder and a plain Quran,

(35) Naught is revealed to me save that I am a plain warner.

(36) And had those who are unjust all that is in the earth and the like of it with it, they would certainly offer it as ransom (to be saved) from the evil of the punishment on the day of resurrection; and what they never thought of shall become plain to them from Allah.

(37) And the evil (consequences) of what they wrought shall become plain to them, and the very thing they mocked at shall beset them.

(38) A Book of which the verses are made plain, an Arabic Quran for a people who know:

(39) He has made plain to you of the religion what He enjoined upon Nuh and that which We have revealed to you and that which We enjoined upon Ibrahim and Musa and Isa that keep to obedience and be not divided therein; hard to the unbelievers is that which you call them to; Allah chooses for Himself whom He pleases, and guides to Himself him who turns (to Him), frequently.

(40) What! that which is made in ornaments and which in contention is unable to make plain speech!