قَدْ أَفْلَحَ مَن تَزَكَّىٰ
Sentence structure
قَدْ confirms the perfect أَفْلَحَ. مَن is its subject, and تَزَكَّىٰ is the relative clause with an understood subject.
Ayah summary
Successful is the one who purifies himself.
قَدْ — Certainly
Grammar: A particle of confirmation preceding a perfect verb.
أَفْلَحَ — has succeeded
Grammar: A third-person masculine-singular Form IV perfect.
مَن — (one) who
Grammar: A relative noun functioning as the nominative subject of أَفْلَحَ.
تَزَكَّىٰ — purifies (himself)
Grammar: A third-person masculine-singular Form V perfect in the relative clause, with understood subject هُوَ.