result of certain morphophonological processes. The voiced plosive is mainly in contrast with . Originally, only occurred as an allophone of before voiced consonants; however, through the influx of loanwords from Arabic it has acquired phonemic status: 'pain'. The glottal fricative occurs as an allophone of ( → 'where?'; → 'of him/her'; → 'I will eat'; → 'he has loved'. This process is unidirectional (i.e. will never change into one of the above consonants) and it has been termed 'consonant switching' () by Werner (1987:36). Only in very few words, if any, does have independent phonemical status: Werner lists 'voice' and 'braying', but it might be noted that the latter example is less convincing because of its probably onomatopoeic nature. The alveolar liquids and are in free variation as in many African languages. The approximant is a voiced labial-velar. Tone Nobiin is a tonal language, in which tone is used to mark lexical contrasts. Tone also figures heavily in morphological derivation. Nobiin has two underlying tones, high and low. A falling tone occurs in certain contexts; this tone can in general be analysed as arising from a high and a low tone together. 'settlement' (high) 'shadow' (low) In Nobiin, every utterance ends in a low tone. This is one of the clearest signs of the occurrence of a boundary tone, realized as a low tone on the last syllable of any prepausal word. The examples below show how the surface tone of the high tone verb ‘cook’ depends on the position of the verb. In the first sentence, the verb is not final (because the question marker is appended) and thus it is realized as high. In the second sentence, the verb is at the end of the utterance, resulting in a low tone on the last syllable. (vegetables:DO cook:she.PRESENT-Q) 'Does she cook the vegetables?' (yes vegetables:DO cook:she.PRESENT) 'Yes, she cooks the vegetables.' Tone plays an important role in several derivational processes. The most common situation involves the loss of the original tone pattern of the derivational base and the subsequent assignment of low tone, along with the affixation of a morpheme or word bringing its own tonal pattern (see below for examples). For a long time, the Nile Nubian languages were thought to be non-tonal; early analyses employed terms like "stress" or "accent" to describe the phenomena now recognized as a tone system. Carl Meinhof reported that only remnants