Topic 28 of 62

البدل والنداء— Apposition & Vocative

بدل renames or restates the preceding noun and takes the SAME case as it — not a fixed case. يا + vocative noun: the noun is مبني على الضم if it's a definite single name (يا محمدُ) or a specific-but-unnamed addressee (نكرة مقصودة), and منصوب if it's an idāfah (يا طالبَ العلمِ) or a non-specific indefinite call.