Hausa

Northern Nigeria (the historical Hausa kingdoms of Kano, Sokoto, Zaria, Katsina, and others) and southern Niger form the core. Hausa serves as a regional lingua franca across West Africa and the Sahel — used in markets, Islamic religious instruction, broadcast media (BBC Hausa, VOA Hausa, Radio France Internationale Hausa), and inter-ethnic communication in Cameroon, Ghana, Sudan, and elsewhere. It's also one of the most internationally broadcast African languages.

Hausa is the largest Chadic language, and Chadic is the largest branch of Afro-Asiatic outside of Semitic. Distant relatives include Arabic, Hebrew, Berber languages, and the Cushitic languages of the Horn of Africa. Within Chadic, most other languages are spoken by much smaller communities scattered around Lake Chad.

Yes — Hausa distinguishes lexical tone with high, low, and falling tones. The same syllable can change meaning depending on its tone, though the tonal load is lighter than in many Sino-Tibetan or Niger-Congo languages. Tone is not normally written in standard Latin-script Hausa, which is one reason learners often pick it up later than other features of the language.

Two: Boko (the Latin-based alphabet, the modern standard) and Ajami (a Perso-Arabic-based script used since at least the 17th century, especially in Islamic and traditional contexts). Modern publishing, news, education, and government use Boko. Ajami persists in religious schools, traditional poetry, and parts of the Hausa diaspora. Both scripts represent the same language.

Yes, two: masculine and feminine. Most masculine nouns end in consonants, most feminine in -a, with exceptions and patterns. Verbs in Hausa don't conjugate for gender, but personal pronouns do, and verb arguments take gender-marked agreement forms in many constructions. Adjectives and possessive markers also agree.