well, yes, thats the idea:
MySQL can use TWO fields for a unique KEY
Language = 1, article = 100, KEY=1100
Language = 2, article = 100, KEY=2100
Language = 1, article = 1000, KEY = 11000. It is similar to CONCAT In a VIEW:
CONCAT(`products`.`language_id`,`products`.`products_id`) AS `main_id`.
The problem is, a VIEW is not insertable.