وَإِذَا ٱلْبِحَارُ فُجِّرَتْ
Sentence structure
In this coordinated condition, ٱلْبِحَارُ is the deputy subject of an omitted passive verb, while فُجِّرَتْ is the explanatory written clause.
Ayah summary
The seas will burst forth, and their fresh and salt waters will merge.
وَإِذَا — And when
Grammar: وَ coordinates the clause; إِذَا is a future non-jussive temporal adverb.
ٱلْبِحَارُ — the seas
Grammar: A nominative definite plural noun; here it is the deputy subject of an omitted passive verb.
فُجِّرَتْ — are made to gush forth
Grammar: A Form II feminine singular perfect passive verb; the written clause is explanatory here.