User:Anakuznetsova/GSOC 2018 Guarani Spanish

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Adoption of Guarani-Spanish language pair in Apertium

GSoC Commits

All the GSoC commits on the project could be found here (post link).

Contacts

Anastasia Kuznetsova

E-mail: menina.indigena.17@gmail.com

GitHub: ana-kuznetsova

Timezone: UTC+3

Project description

A project of adoption of Guarani-Spanish language pair in Apertium had as its purpose a creation of machine translation system between Guarani and Spanish languages. As Guarani is one of the low-resource languages of the world the translation system is unlikely to be developed by other methods than Rule-Based Machine Translation. As the evidence of that we had only about 2800 texts from Wikipedia dumps [1] and Guarani-Spanish aligned Bible [2] as a source.

Generally project consisted of three main parts:

  • Morphological analyzer for Guarani
  • Guarani-Spanish bilingual dictionary (bidix)
  • Transfer rules

A detailed work plan for the project can be found here.

Morphological Analyzer

We had to develop morphological analyzer almost from scratch. And the most challenging thing from the beginning was to find any properly organized lists of words or Guarani dictionaries. By the end of the Community Bonding period after 2 week of work we were able to analyze only 30% of words contained in wiki corpora. Coverage reached (?) % by the end of Google Summer of Code program.

All in all our morphological analyzer contains 12 638 lemmas:

  • 4455 Nouns
  • 2537 Verbs (divided in two groups by transitivity)
  • 1668 Adjectives
  • 457 Adverbs

This list does not include other lemma categories such as Proper Names (3052), different kind of pronouns, barbarisms (more frequently borrowed from Spanish), interjections, etc.

But we are able to analyze even more because some of them have orthographical equivalents (as there are several traditions in written Guarani) or some forms found in corpora are just spelling errors.

Sources

Here are some sources that we used to construct morphological dictionary.

  1. Discubrir Corrientes. La Enciclopedia Virtual Correntina ;
  2. Low Resource Language Dictionaries.

In addition we have managed to do some syntactic tree annotation for some of the texts from our wiki corpora, although it is on the initial stage and requires corrections.

Example of annotation made by morph analyzer:

echo "Ou omba'apo hag̃ua" | lt-proc grn.automorf.bin

^Ou/Ou<v><iv><pres>/Ou<v><iv><p2><sg><pres>/Ou<v><iv><p3><pl><pres>$
^omba'apo/o<prn><pos><p3><sg>+mbaʼapo<n>$ ^hag̃ua/hag̃ua<post>$

Vino a trabajo. 

Although we did not do any disambiguation so far.