It's a contradictory sentence. I'm used to saying "a film" for good ones and "a movie" for your typical run-of-the-mill Hollywood entertainment junk - and the latter never get sad endings ;-)
I wasn't aware of that distinction. For me (in the UK) "film" is the usual word, "movie" a definite Americanism. A typical Hollywood "movie" is more likely to be junk, but the word in itself doesn't convey a quality judgement for me. I'd just think: "Oh, that's American for what I call a film." It might or might not be any good.
But repeatedly promoting films as "movies" over here is slightly grating to my ears, even if it doesn't necessarily have any bearing on whether they're any good.
While i find the two terms to be used interchangeably here in the midwest USA, "film" definitely gives a conotation that it is potentially art, and "movie" being more generic/slangy, and if anything, like said above, it may be garbage, so it is surprising anyone would want to market their work as a "movie".
It's just about possible you might say this, but not very likely. There are many possible sad ends, not just one, so you are far more likely to say a movie has a sad end than THE sad end.
Ok, thanks. But can I use "the sad end" when I and my interlocutor know about the end? E.g. we already watched this movie with this sad end and we know about it.
Yes, it could happen. If someone asks: "What did you think of the film?", you might reply: "It was a shame about THE sad ending". It's just less common. Also "sad ending" is better than "sad end". Please don't ask me why - it just is. ;) When talking about a book, film or play, it's more common to talk about the ending, rather than the end. If you talk about "a sad end", it's more likely to be about a person (died in a tragic way), or maybe even a building or organisation that was once great or famous, but has now gone.