still not as a separate language from the Northern and Southern Sotho languages) was published by the French missionary, E. Casalis in 1841. He changed his mind later, and in a publication from 1882, he noted that the Northern and Southern Sotho languages were distinct from Tswana. Solomon Plaatje, a South African intellectual and linguist, was one of the first writers to extensively write in and about the Tswana language. Phonology Vowels The vowel inventory of Tswana can be seen below. Some dialects have two additional vowels, the close-mid vowels and . The circumflex on e and o in general Setswana writing is only encouraged at elementary levels of education and not at upper primary or higher; usually these are written without the circumflex. Consonants The consonant inventory of Tswana can be seen below. The consonant is merely an allophone of , when the latter is followed by the vowels or . Two more sounds, v and z , exist only in loanwords. Tswana also has three click consonants, but these are only used in interjections or ideophones, and tend only to be used by the older generation, and are therefore falling out of use. The three click consonants are the dental click , orthographically ; the lateral click , orthographically ; and the palatal click , orthographically . There are some minor dialectal variations among the consonants between speakers of Tswana. For instance, is realised as either or by many speakers; is realised as in most dialects; and and are realised as and in northern dialects. The consonant can exist at the end of a word without being followed by a vowel (as in Jwaneng and Barolong Seboni). Stress Stress is fixed in Tswana and thus always falls on the penult of a word, although some compounds may receive a secondary stress in the first part of the word. The syllable on which the stress falls is lengthened. Thus, mosadi (woman) is realised as . Tone Tswana has two tones, high and low, but the latter has a much wider distribution in words than the former. Tones are not marked orthographically, which may lead to ambiguity. go bua "to speak" go bua "to skin an animal" o bua Setswana "He speaks Setswana" o bua Setswana "You speak Setswana" An important feature of the tones is the so-called spreading of the high tone. If a syllable bears a high tone,