kuntum
you used to
V – 2nd person masculine plural perfect verb + PRON – subject pronoun tum
Root Link: ك و ن
bihi
[about it]
P – prefixed preposition bi + PRON – 3rd person masculine singular personal pronoun hi
Root Link: ب
tamtarūna
doubt
V – 2nd person masculine plural (form VIII) imperfect verb + PRON – subject pronoun ūna
Root Link: م ر ى