وَأَمَّا بِنِعْمَةِ رَبِّكَ فَحَدِّثْ
Sentence structure
وَأَمَّا introduces the final branch. بِنِعْمَةِ رَبِّكَ is a fronted prepositional phrase; فَحَدِّثْ is the imperative response with understood subject أَنْتَ.
Ayah summary
And speak of your Lord's blessings with gratitude.
وَأَمَّا — And as for
Grammar: وَ coordinates and أَمَّا introduces the final detailed branch.
بِنِعْمَةِ — the favor
Grammar: بِ is a preposition and نِعْمَةِ a feminine genitive noun annexed onward. This phrase is linked to «حَدِّثْ».
رَبِّكَ — of your Lord
Grammar: A masculine genitive complement; attached كَ is its possessor.
فَحَدِّثْ — then proclaim
Grammar: فَ introduces the response; حَدِّثْ is Form II imperative with understood subject أَنْتَ.