Norman was already a bit weird vis-a-vis Parisian. Maybe have France develop into a more Occitanian centred country so it is closer to Spanish and Italian?
It would be preferred to have modern ATL French remain the same as the modern OTL French, but have Anglais diverge from it.
Leej said:
Then maybe move a lot of Irish or Welsh into England too so they can bring some celtic weirdness?
That could definitely be a major contributing factor. The original POD stated that Anglais need only be the language of England, not Scotland, Wales, or Ireland. So if we assume, somehow, that Welsh and Gaelic (both Scottish and Irish) remain strong in their native lands, and that Anglais does not come to dominate for some reason, that could mean there are a lot of loan words and diffusion along the borders.
Another factor that might contribute to such an outcome would be an earlier and more complete political severance between England and France, which leads the Normans in England to think of themselves as "Anglais" rather than "Norman." They then consciously make an effort to differentiate themselves...and their language...from that of the "Old Country." This would be similar to what happened in Norway, for example, in OTL, IIRC. Norwegians spoke Danish up until the mid to late 19th century, when a conscious nationalist movement basically created enough divergences for a new language to emerge...the Norwegian language. If something like that could occur in such a short time, Anglais, given a much longer period to diverge from French, could end up quite different.
So what PODs could create these factors...
1) Stronger survival and prospering of Welsh and Gaelic, and less influence of English/Anglais over them?
2) Earlier severing of political relations and cultural bonds between England and France, and a nationalist move to
differentiate Anglais from French?