I hate to say it but I think American is a purer form of English, because of the French influence in the UK, I would really like to be wrong about this ��
We have a saying in Welsh that covers that;
"Cachu ci, cachu cath, cachu mochyn - jyst ru'n fath"
But in all seriousness, a couple of points;
English has been a b'stardised (I'm not swearing, honest - that's a proper word, that!) language long before there was ever a US/English divide - and any French influence has been in place loooong before the seperation of the two languages would have had any effect. For example - you still use "rendezvous" and "restaurant" in the US. I doubt there are any "modern" French words which have supposedly made it into modern "EnglishEnglish", and yet avoided inclusion into "AmericanEnglish".
Secondly - you could very much argue that American English is just as "impure" (if you really want to talk about "purity" of a language - see the last point) except the main source of "contamination" would be Spanish. With that I'd say there's
much more of an active crossover with Spanish-American than there is with French in the UK.
Thirdly - do you realise how ridiculous it is to say that any one language is more "pure" than another? The very
nature of language is to change. To morph. To include, diversify and expand. There is
no such thing as a pure language - going back to my Welsh proverb, which translates as (gonna be careful with the forum on this one);
"Cat poo, dog poo, pig poo - it's all just poo"
...or, ofc, you're just trolling. In which case, you did good. You got a response.
PS; As an aside, I am (somewhat obviously) a Welsh speaker and I live in England. Whenever I'm talking in Welsh to friends/family naturally some English words make their way into the conversation... The amount of grief/stick I get for "not having [our] own words" for some things is amazing... I always respond with the rendezvous/restaurant examples - I find it very amusing (read: hypocritical) to comment on another language's appropriation of words when English itself (and arguably all languages since the dawn of time) is one of the "worst" examples of word appropriation.
I do find it rather amusing when people defend the sanctity of their language so vehemently (oooh, look at me using all those big words...) when in fact all languages are in a state of transition, not stagnation. They all evolve, they all change, they all incorporate parts of each other. Each generation brings new words and meanings into the fold, and as each generation passes on more words and meanings are lost, and people forget that the "now" is just a snapshot of the overall change taking place.
Ahem. Rant over.