Can English and Catalan Switch places with Catalan as International Linguafranca like in the Middle Ages while English survives in the same way as OTL Catalan and French dominates in England but English is as strong as OTL Catalan..
Have a strong Catalan-speaking state emerge and expand onto Corsica and Sardinia and beyond.
Perhaps the defeat of France in the Cathar crusade would do the job.
Or keep France as it was: fragmented and what not.