Complex sentence: Nilo-Saharan is a controversial grouping uniting over a hundred extremely diverse languages from southern and northern Egypt to northern Tanzania and into Nigeria and DR Congo, with the Songhay languages along the middle reaches of the Niger River as a geographic outlier.
Split into simpler sentences: Nilo-Saharan is a controversial grouping uniting over a hundred extremely diverse languages. It has a speech area that stretches from the Nile Valley to northern Tanzania and into Nigeria and DR Congo, with the Songhay languages along the middle reaches of the Niger River as a geographic outlier.