Stem ظَنَن has 3 unique word forms and appears 7 times in the Quran.

Word Translation Occurrences
ظَنَنتُمۡ you assumed, you think, you thought 8
ظَنَنتُ was certain 2
ظَنَنتُم you assumed 2
وَظَنَنتُمۡ And you assumed 2