In Asterisk, Queues, IVRs, etc. are not associated with a particular language. Asterisk attempts to play all prompts in the caller’s language. Calls originated locally default to the language of the Extension. External incoming calls default to the language of the Inbound Route.
If routed to a queue, caller position, estimated wait time and other built-in announcements will play in the language selected by the Extension or Inbound Route.
If you provide service in multiple languages on the same number, set up an IVR that asks for the caller’s language. Each IVR entry routes to a Languages destination, which sets the desired language then routes to a queue (same or different, depending on whether the agents are bilingual).