To ð or not to ð - A F aroese CG -based grammar checker targeting ð errors (2023)

Abstract: Many errors in Faroese writing are linked to the letter ð, a letter which has no corresponding phoneme, and is always omitted intervocally and wordfinally after a vowel. It plays an important role in the written language, disambiguating homophone but not homograph forms like infinitive kasta ‘throw’ from its participle kastað. Since adding a hypercorrect ð or erroneously omitting it often results in an existing word, these errors cannot be captured by ordinary spellcheckers. The article presents a grammar checker targeting ð errors, and discusses challenges related to false alarms.

## introduction the article addresses a central problem in written faroese: how to correct errors arising from erroneously writing or omitting the letter ð in such a way that the resulting errouneous form is an existing word. a typical case of ð omission is (1), and an instance of superfluous ð is (2) foot_0 . the challenge is to correct such errors. the approach presented here is to build a grammar checker on top of a grammatical analysis of faroese, where the erroneous patterns are identified and the correct forms are presented to the user, accompanied by an explanation. the grammar checker is already part of the web-based version of the faroese spell checker foot_1 , and the main challenge at the present stage is thus to have a good precision. testing the recall of the grammar checker is obviously relevant for a thorough evaluation, but this falls outside the scope of the present article. the article is structured as follows. first, section 2 shortly presents relevant aspects of faroese and of the morphological and grammatical components providing the input to the grammar checker. section 3 presents the grammar checker. section 4 presents the evaluation material and discusses the results. finally comes a conclusion. ## conclusion this article has presented an early version of a faroese grammar checker, targeting errors related to inflectional forms containing the suffix ð. even though the grammar checker still contains some obvious errors, the precision is quite good, over 80 % for the most frequent ð error type. with these errors corrected as well as an improved suggestion component, the present grammar checker may be seen as both a welcome addition to the faroese spell checker as well as a pedagogical tool for pupils during the learning process. the next steps for the grammar checker are to investigate the recall of the error types it already covers (to look at the ð errors the grammar checker fails to capture), and to include more error types. this is left for future research.