AI will speak an own language that will be built the way humans could get it. My point is about practical reasons while free will is more complex idea.

Pidgin language is a grammatically simplified means of communication that develops between two or more groups that do not have a language in common[wikipedia].

AI architecture probably will be different from human brains so it will look for intermediate language that fits for both minds. Here is 2steps:

• When AI is less powerful that human — people have to learn machine language.
• When AI is more powerful — it could speak native English or any other language.