Carlos Serra wonders if there are more, according to two renowned linguists: "One told me that there were between 20 and 26; the other told me that there were 17 written and some yet to be spelled out". 
Carlos Serra anajiuliza kama kuna lugha nyingine zaidi, kwa mujibu wa wataalamu wa lugha mashuhuri:"Kuna mtu aliniambia kuwa zipo kati ya 20 na 26; mwingine akaniambia zipo 17 zilizoandikwa na nyingine bado hazijaweza kuandikwa".