In order to ensure your lists' hygiene and diminish risks (such as spam complaints or invalid emails, you should only use one master list, divided by groups.
Learn more about creating and managing groups.
Each list can only have one language. If you have a multilingual customer base, you will need to create one list per language you do business in.
Note: If you change the language of the list, you need to edit the confirmation and welcome emails manually. Please remember that confirmation and welcome emails cannot be edited within a trial account.