Please only contribute in languages that you are familiar with. The whole purpose of this project is to avoid simply using online translation software, since it often fails badly with mathematical terminology!
When translating, please also check the Wikidata links (shown by hovering over the word to be translated) to ensure that the word is being used in the same way as you think (lots of words, such as "base", have lots of meanings, and so are often translated to multiple different words in other languages, depending on the context).