وَإِذَا ٱلْكَوَاكِبُ ٱنتَثَرَتْ
Sentence structure
وَإِذَا coordinates another condition. Here, ٱلْكَوَاكِبُ is the subject of an omitted active verb and ٱنتَثَرَتْ is its explanatory clause.
Ayah summary
The stars will fall from their places and scatter.
وَإِذَا — And when
Grammar: وَ coordinates the clause; إِذَا is a future non-jussive temporal adverb.
ٱلْكَوَاكِبُ — the stars
Grammar: A nominative definite plural noun; here it is the subject of an omitted active verb.
ٱنتَثَرَتْ — scatter
Grammar: A Form VIII feminine singular perfect active verb; the written clause is explanatory here.