Tehrani accent (Persian: لهجهٔ تهرانی‎‎) is a dialect of modern Persian language spoken in Tehran Province, and the most common colloquial variant of the modern Persian language. Compared to literary standard Persian, the Tehrani dialect lacks original Persian diphthongs and tends to fuse certain sounds. The Tehrani accent of Persian language should not be confused with the Old Tehrani dialect, which was a northwestern Iranian dialect, belonging to the central group.