@DavidC96 I can't really tell the difference between British and American when they speak French, so I'd speak about Anglophones generally : I think that they have a hard time pronouncing "r", "u" and the nasal vowels like "on", "in" or "an". They often pronounce u like "ou" and they mix "on" "in" "an" etc.
yes maybe but not exactly... I made some research on the internet and now I am able to explain it better to you : Languages like most of the Roman languages, for example, are tonic accents languages : some syllabus are pronounced stronger than the others. For example, in the word "castle", you pronounce it CAstel, with the accent on the first syllabus. But in French, these accents are really soft, especially compared to other Roman languages (wich explains why French native speakers tend to not really pronounce the accent when we speak English or other foreign languages)