وَٱلَّذِينَ كَفَرُوا۟ بِـَٔايَـٰتِنَا هُمْ أَصْحَـٰبُ ٱلْمَشْـَٔمَةِ
Sentence structure
وَٱلَّذِينَ begins a coordinated topic; كَفَرُوا۟ بِـَٔايَـٰتِنَا is its relative clause. هُمْ أَصْحَـٰبُ ٱلْمَشْـَٔمَةِ is the predicate nominal clause: هُمْ is its topic and أَصْحَـٰبُ its predicate.
Ayah summary
Those who reject Our signs are the unfortunate people of the left side.
وَٱلَّذِينَ — But those who
Grammar: وَ coordinates and ٱلَّذِينَ is a masculine-plural relative pronoun functioning as topic.
كَفَرُوا۟ — disbelieve
Grammar: A third-person masculine-plural perfect; attached وا۟ is the subject and the clause completes ٱلَّذِينَ.
بِـَٔايَـٰتِنَا — in Our Verses
Grammar: بِ is a preposition; ءَايَـٰتِ is a feminine-plural genitive noun and attached نَا its possessor. This phrase is linked to «كَفَرُوا۟».
هُمْ — they
Grammar: A third-person masculine-plural detached pronoun functioning as the topic of the predicate nominal clause.
أَصْحَـٰبُ — (are the) companions
Grammar: A masculine-plural nominative predicate of هُمْ, annexed to the following noun.
ٱلْمَشْـَٔمَةِ — (of) the left (hand)
Grammar: ٱل defines the feminine genitive complement of أَصْحَـٰبُ.