A frican W ordnet: facilitating language learning in A frican languages (2018)

Abstract: The development of the African Wordnet (AWN) has reached a stage of maturity where the first steps towards an application can be attempted. The AWN is based on the expand method, and to compensate for the general resource scarceness of the African languages, various development strategies were used. The aim of this paper is to investigate the usefulness of the current isiZulu Wordnet in an application such as language learning. The advantage of incorporating the wordnet of a language into a language learning system is that it provides learners with an integrated application to enhance their learning experience by means of the unique sense identification features of wordnets. In this paper it will be demonstrated by means of a variety of examples within the context of a basic free online course how the isiZulu Wordnet can offer the language learner improved decision support.

## introduction the development of the african wordnet (awn) containing wordnets for five african languages, namely setswana (tsn), isixhosa (xho), isizulu (zul), sesotho sa leboa (nso) and tshivenda (ven), has reached a stage of maturity where the first steps towards an application can be attempted. the aim of this paper is to investigate the usefulness of the current isizulu wordnet 1 in an application such as language learning. against the background of a multi-lingual scenario of eleven official languages of south africa, the national development plan 2030 (ndp) enjoins all south africans to learn at least one indigenous language as part of nation-building and social cohesion @xcite . such an imperative calls for prioritizing the development of language learning courses. currently, very limited material exists to support language learners who wish to focus on improving their skills in their own time, without much cost involved and with actual real-world examples. most of the material developed to engage learners of an african language, are either taught in time-consuming (university) classes or after purchasing expensive software with generic course content and teaching style. an exception is a set of basic free online courses learn to speak an african language (letsal) (university of south africa, 2010) that were developed for first time language learners of some of the indigenous south african languages, namely setswana, isixhosa, isizulu, sesotho and sesotho sa leboa. although the african languages can still be regarded as under-resourced (cf. the resource audit performed by grover, @xcite the african wordnet (awn) project reported in @xcite , has played a significant role in filling the gap as available source of data for further human language technology and linguistic research. the individual african languages wordnets, with less than 20,000 synsets per language, are still relatively small in comparison to some of the large wordnets such as the princeton wordnet foot_0 (117 659 synsets for english) and the finnwordnet foot_1 (120 449 synsets for finnish). nevertheless, we investigate the possibility of using the awn effectively as support for language learners in a computer assisted language learning (call) environment. our focus is on isizulu. in this paper, the interaction between the awn and letsal will be explored as a first step towards moving to a more integrated call system, with a focus on improving user interaction. a brief background to both the awn and letsal will be provided, before the contents of the two resources is assessed. we also discuss ways to integrate the awn into the current letsal system, with a view on moving towards an intelligent call (icall) application as proposed in @xcite . fast-tracking the expansion of the awn with letsal data is also shown to be effective, even with minimal additional resources. ## background in this section, we discuss the status quo of the african wordnet as potential language learning support resource and provide background on the letsal courses. ## incorporating awn in letsal as additional reference material the advantages of incorporating all available natural language processing (nlp) resources for a language into a call system, is that learners are offered an integrated application to enhance their understanding of the subject matter. in a related study, @xcite describes colliea collaborative language learning and instruction environment for japanese foreign language learners. this system combines advanced nlp tools such as machine translation and complex analysers with the english pwn and the japanese wordnet to provide learners with translations of japanese webpages, as well as detailed information on the word level. "all this information is very useful as decision support for selecting the word sense, reading, and english translation of a japanese word" @xcite . while nlp support is still limited for isizulu, it is important that we integrate the resources that are freely available and use them to the best advantage of language learners. the learner improved decision support that can be offered by the isizulu awn, which typically covers a variety of semantic relations including synonymy and antonymy, along with usage example sentences and definitions, will be demonstrated by means of a selection of examples within the context of letsal. each of the example words already occur in the letsal course material, but only with the english translation and no further information on meaning nuances or associated misconceptions in isizulu. to illustrate the need for more disambiguating context and the type of information that a language learner might also find useful, we combined information from the isizulu awn and the relevant information from the english pwn (princeton university, 2017) in tables 1 -10. the significance of these examples is discussed, before a suggestion for improving the current letsal environment with similar information is made at the end of this section. isizulu and most of the languages belonging to the bantu language family are known as tone languages in which pitch variation plays a role in conveying lexical as well as grammatical distinctions foot_4 (cf. @xcite @xcite . the two basic tone levels that can be distinguished in isizulu, namely high (h) and low (l), may be marked by means of placing acute and grave accents above the syllables of a word, or by placing the symbols h and l after the word, e.g. in the following pairs of nouns and verb stems it is illustrated how tone distinguishes meaning: íthàngá (thigh) hlh íthàngà (pumpkin) hll ínyàngá (moon; month) hlh ínyàngà (herbalist) hll -dúmà (be tasteless) hl -dùmá (roar, be famous) lh since tone is not, however, marked in the standard orthography of isizulu, language learners are often confronted with a difficult choice between two meanings of (seemingly) the same word. it should also be noted that tones are not absolute. tones documented in dictionaries usually refer to tones of the word as it occurs in isolation or in sentence final position. in other sentence positions, tones may undergo various changes.