Use Revolutionâ€™s Lexicons.
In your chunk:
[[%lexicon_entry_key? &topic=`topicName` &namespace=`namespaceName`]]
So, say you put all your langauge files in the â€™mysiteâ€™ Namespace (Namespaces can be used to group lexicon entries and topics), and had a Topic called â€™sportsâ€™. You can create as many Topics as you like. Say you want to grab the Lexicon Entry with the key â€™welcome_messageâ€™ from the Topic â€™sportsâ€™.
Youâ€™d then put this in your chunk:
[[%welcome_message? &topic=`sports` &namespace=`mysite`]]
This would then render the translation (depending on what language youâ€™ve initialized that Context in) for the Lexicon Entry â€™welcome_messageâ€™. It would also load the â€™sportsâ€™ Topic and â€™mysiteâ€™ Namespace. You only need to load the Topic/Namespace once on a page.
MODx recommends you prefix your Lexicon Entries with some prefix to distinguish them from other Components Lexicon Entries. But you can do it however you want.
Please read the Internationalization Documentation
for Revolution for more information.