When you're young, you learn how to describe things from those around you. This is when you learn to call carbonated drinks "Cokes" in the South or "pop" if you're, well, wrong. Before this goes off the rails, though, we're focusing on language as it pertains to movies. Just a little informal sampling, and I hope you'll respond with your personal preferences.
"Film" or "Movie" - They're synonymous, though there is a pretentious school of thought that likes to consider highbrow, artistic works "films" and mainstream fare "movies" as though there's some value to using one word over the other.
"Cinema" or "Theater" - Where do you go see a movie (or film)? Also, if you favor "Theater," do you transpose the "er" to "re" to become "Theatre?"
Actor or Character - When describing a plot, do you find yourself saying, "Harrison Ford is accused of killing a woman" or "Harrison Ford plays a guy accused of killing a woman?" (Bonus point if you can name the story.)
"Part One" - If you're talking about a movie series, do you find yourself adding "One" at the end of the title of the first movie? For instance, "I liked Godfather 'I' better than Godfather II."
"Direct" vs. "Make" - Fairly synonymous, though one is more specific. Did Martin Scorsese "direct" or "make" The Departed?
"Star in" vs. "Make" - Same difference as "Directed." Did Sean Connery "star in" or "make" Medicine Man?
Remember, this isn't one of those "choose which one is most correct" tests. I'm just curious which terms you personally find yourself using most often.