What are the main differences between depend on and depend upon? I read somewhere: "depend upon- means when an action is dependant upon something else. Which means, in order for something to occur, another thing must happen first. ex."I can go to the movie, but it depends upon whether my parents will let me." Wanted to make sure whether is it right or not and what are the main differences between depend on and depend upon in general? Thank you for your response.