Complex sentence: Chewa is the national language of the Republic of Malawi, it is also one of the seven official African languages of Zambia, where it is spoken mostly in the Eastern Province and in Lusaka.
Split into simpler sentences: Chewa is the national language of the Republic of Malawi. It is also one of the seven official African languages of Zambia, where it is spoken mostly in the Eastern Province and in Lusaka.