The word(s) "certain" appears 144 time(s) in 135 verse(s) in Quran in Abdullah Yusuf Ali translation.

(41) Allah is He Who raised the heavens without any pillars that ye can see; is firmly established on the throne (of authority); He has subjected the sun and the moon (to his Law)! Each one runs (its course) for a term appointed. He doth regulate all affairs, explaining the signs in detail, that ye may believe with certainty in the meeting with your Lord.

(42) "No reason have we why we should not put our trust on Allah. Indeed He Has guided us to the Ways we (follow). We shall certainly bear with patience all the hurt you may cause us. For those who put their trust should put their trust on Allah."

(43) And there is not a thing but its (sources and) treasures (inexhaustible) are with Us; but We only send down thereof in due and ascertainable measures.

(44) "Excepting the adherents of Lut: them we are certainly (charged) to save (from harm),- All -

(45) "Except his wife, who, We have ascertained, will be among those who will lag behind."

(46) Strain not thine eyes. (Wistfully) at what We have bestowed on certain classes of them, nor grieve over them: but lower thy wing (in gentleness) to the believers.

(47) And serve thy Lord until there come unto thee the Hour that is certain.

(48) And they (even) assign, to things they do not know, a portion out of that which We have bestowed for their sustenance! By Allah, ye shall certainly be called to account for your false inventions.

(49) And be not like a woman who breaks into untwisted strands the yarn which she has spun, after it has become strong. Nor take your oaths to practise deception between yourselves, lest one party should be more numerous than another: for Allah will test you by this; and on the Day of Judgment He will certainly make clear to you (the truth of) that wherein ye disagree.

(50) If Allah so willed, He could make you all one people: But He leaves straying whom He pleases, and He guides whom He pleases: but ye shall certainly be called to account for all your actions.