taqūlū
you say
V – 2nd person masculine plural imperfect verb, subjunctive mood + PRON – subject pronoun waw
Root Link: ق و ل
unzila
was revealed
V – 3rd person masculine singular (form IV) passive perfect verb
Root Link: ن ز ل
kunnā
we were
V – 1st person plural perfect verb + PRON – 1st person plural object pronoun nā
Root Link: ك و ن
dirāsatihim
their study
N – genitive feminine noun + PRON – 3rd person masculine plural object pronoun Ha
Root Link: د ر س
laghāfilīna
certainly unaware
EMPH – emphatic prefix lām + N – accusative masculine plural active participle
Root Link: غ ف ل