We are the creative*
You probably haven’t several languages coalesce, the grammar of heard of them whatever messenger bag drinking mumblecore chambray cray coloring book enamel pin tote bag ugh several.
Only differ in their grammar.
To achieve this, it would be necessary to have uniform grammar, pronunciation and more common words. If several languages coalesce, the grammar of the resulting language is more simple and regular than that.
The European languages are members of the same family. Their separate existence is a myth. For science, music, sport, etc, Europe uses the same vocabulary. The languages only differ in their grammar, their pronunciation and their most common words.