From a reader…
Is it possible to say Mass in many languages? In example part in English, part in French or better part in English and Canon in latin?
Yes, this is possible in the Ordinary Form.
Is it a good idea?
I don’t think so.
If there is a group of people (who all belong to the Latin Church) speaking different languages, why not use everyone’s language, Latin? People can have their own translations.
(And, no, I am not fan of the multiple language papal Masses either.)