Welcome to the phpList translators home page on our community exchange. Full documentation on how to translate phpList can be found here, but Below are some super-simple-summaries to help you on your way.

I want to suggest a better word/phrase

Locate the language, then the phrase in our translation area
Review existing suggestions
Suggest a better word

Feeling confident? If several people have suggested the same word as you, or if you are sure your suggestion is correct, then why not edit the word directly.

I want to edit a word/phrase in a translation

Create a Weblate account here and indicate your languages
Join the translators email list and ask for editor status
Locate the language, then word/phrase in the translation area
Review suggestions, does it look like people agree with you?
Submit a word

I want to write a new translation or complete an unfinished one

 Join the translators email list
Create a translate.phplist.com Weblate account and indicate your languages.
Collaborate: tell the mailinglist to tell everyone what language you want to translate – perhaps some other people would like to help you
Translate: work your way through the translation until your language is 100%

Additionally, there are some help and info texts to translate in github. Here, here and here. There are two ways to complete and submit these translations. You can copy the English files and edit them, keeping the file-names the same, and email them to the translators mailing list, OR you use git/github to fork them and make a pull request.

Also why not

Join the phpList community here
Join the translation mailing list here