Igbo

Mostly in the southeastern Nigerian states of Abia, Anambra, Ebonyi, Enugu, and Imo, plus parts of Delta and Rivers. Igbo communities also live across other Nigerian states and across the diaspora — particularly in the United States, the United Kingdom, Canada, and South Africa. It's one of the three major Nigerian languages alongside Hausa and Yoruba.

Two — high and low — with tone shaping word meaning, grammatical role, and sentence interpretation. The same syllable can mean different things depending on tone, and tone changes across grammatical contexts (downstep tones) are systematic but invisible to learners who haven't been trained to hear them. Tone is marked with diacritics in standardized Igbo writing.

Igbo splits its vowels into two sets based on tongue-root position (advanced vs retracted), and within a word the vowels generally have to come from the same set. This affects affixes — verb prefixes and suffixes shift their vowels to match the verb root. The system is more subtle than Turkish vowel harmony but operates on the same principle of harmony within a phonological domain.

Threatened, particularly in urban Nigeria. Some surveys suggest Igbo transmission to younger generations has weakened in upper-middle-class urban families who use English with their children. UNESCO classified Igbo as 'vulnerable' in some assessments. Active language-revival movements, including media production, university programs, and online community efforts, are working against the trend.

Yes. The standard 'Central Igbo' is a 20th-century literary creation drawing on several regional varieties; spoken Igbo includes a wide range of regional dialects (Owerri, Onitsha, Awka, Nsukka, Ngwa, etc.) that differ noticeably in pronunciation and vocabulary. Some dialect divergences are large enough that mutual intelligibility requires effort, particularly between northern and southern Igbo varieties.