sentences:  In 1976, the "Société Zaïroise des Linguistes" (Zairian Linguists Society) adopted a writing system for Lingala, using the open e and the open o to write the vowels and , and sporadic usage of accents to mark tone, though the limitation of input methods prevents Lingala writers from easily using the and and the accents.For example, it is almost impossible to type Lingala according to that convention with a common English or French keyboard.The convention of 1976 reduced the alternative orthography of characters but did not enforce tone marking.