The word(s) "couldst" appears 14 time(s) in 14 verse(s) in Quran in Muhammad Pickthal translation.

(11) And as for the wall, it belonged to two orphan boys in the city, and there was beneath it a treasure belonging to them, and their father had been righteous, and thy Lord intended that they should come to their full strength and should bring forth their treasure as a mercy from their Lord; and I did it not upon my own command. Such is the interpretation of that wherewith thou couldst not bear.

(12) couldst thou but see when the guilty hang their heads before their Lord, (and say): Our Lord! We have now seen and heard, so send us back; we will do right, now we are sure.

(13) And those who disbelieve say: We believe not in this Qur'an nor in that which was before it; but oh, if thou couldst see, when the wrong-doers are brought up before their Lord, how they cast the blame one to another; how those who were despised (in the earth) say unto those who were proud: But for you, we should have been believers.

(14) couldst thou but see when they are terrified with no escape, and are seized from near at hand,