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

(11) And remember when He made you successors after Ad and settled you in the land-- you make mansions on its plains and hew out houses in the mountains-- remember therefore Allah's benefits and do not act corruptly in the land, making mischief.

(12) Do they not reflect that their companion has not unsoundness in mind; he is only a plain warner.

(13) The hypocrites fear lest a chapter should be sent down to them telling them plainly of what is in their hearts. Say: Go on mocking, surely Allah will bring forth what you fear.

(14) Alif Lam Ra (This is) a Book, whose verses are made decisive, then are they made plain, from the Wise, All-aware:

(15) And certainly We sent Nuh to his people: Surely I am a plain warner for you:

(16) And the king said: Surely I see seven fat kine which seven lean ones devoured; and seven green ears and (seven) others dry: O chiefs! explain to me my dream, if you can interpret the dream.

(17) Yusuf! O truthful one! explain to us seven fat kine which seven lean ones devoured, and seven green ears and (seven) others dry, that I may go back to the people so that they may know.

(18) He said: I only complain of my grief and sorrow to Allah, and I know from Allah what you do not know.

(19) And We did not send any apostle but with the language of his people, so that he might explain to them clearly; then Allah makes whom He pleases err and He guides whom He pleases and He is the Mighty, the Wise.

(20) And say: Surely I am the plain warner.