This seems a good Movie to watch, though I prefer to spend time #gaming (It was good to read about it in your post though.)

Now about how language isn't affected by the amnesia, it's because the part of the brain responsible for the language and facts is different than the part responsible for memories. A person with that type of amnesia can know that apples are red but don't remember ever tasting one.

There are types of memory loss that stops you from being able to form a scentence but I don't know if it's called amnesia.