Complex sentence: The speaker population calls their own language (with prenasalised), which may be rendered "Amba" or "Aba" depending on spelling conventions, which have not been fixed yet for these languages.
Split into simpler sentences: The speaker population calls their own language (with prenasalised). This name may be rendered "Amba" or "Aba" depending on spelling conventions, which have not been fixed yet for these languages.