Liferay's community extends to virtually every continent and country in the world and is offered in many languages. If you'd like to add or improve on Liferay's translations, join the Translation Team for your desired language(s) and help us make Liferay a more accessible project for speakers of the world's languages.
Contact the Translation Team to find out if your language is supported by Liferay, and if there are active contributors. Post a message on the Translation Team forum stating you'd like to join the team and help out.
Read the How to Translate Liferay guide.
Select the project for which you'd like to provide a translation, then select the language, then you can start contributing your translations right away!