American English throughout and easy to follow. No problem for pre-intermediate and above.
Christmas films are an interesting sub-genre of cinema, they can be about Christmas, "The Santa Clause", they can be set at Christmas like "Die Hard" and "The Long Kiss Goodnight", they can be animated "Arthur Christmas", "The Grinch", comedies, "Scrooged" and they can be fantasy, adventure or romantic, "Miracle on 34th Street"
But my pick for Christmas Film has to be Home Alone. It's a wonderful mix of humour and family-friendly story that really hits whether you are ten years old or fifty. I watched it again only last night with my children and, apart from the odd question about phones (mobile phones would render the whole film pointless!) it hasn't aged at all.
You all know the story, and with Joe Pesci, Daniel Stern, Catherine ÓHara and even John Candy helping the brilliant Macauley Culkin in the acting department, it just works.
And never forget the The South Bend Shovel Slayer!