An American movie set in France depicts a number of German tourists speaking Russian with a Swedish accent.
Zig Zagged: The French characters' lines alternate between plain English, French-accented English, French with English subtitles, French without English subtitles, French with non-English subtitles, random other languages with varying types of subtitles, and random gibberish with varying types of subtitles, sometimes within the same conversation.
Averted: Tropers is an American movie set in France, and all of the main characters (or at least all the locals) speak French.
The movie is released in America and needs to bring a large audience in order for the director to keep working. Therefore, everyone speaks English, despite being set in France.
The director couldn't find enough (or good enough) French-speaking actors.
Lampshaded: Alice complains about everyone speaking English in France.
Invoked: Alice is filming a documentary about life in France, and tells everyone to speak English to allow the English audience to understand.
Exploited: Alice is moving to France and doesn't bother learning the language, because she knows everyone will speak English.
Defied: "Stop speaking English! We are in France, we all know French, lets speak French, for heavens sake!"
Discussed: Alice, an American, arrives in France. When she doesn't understand anything, Bob explains that in Real Life, the French speak French.
Conversed: "Why do characters in French movies always speak English with a French accent?"
Deconstructed: English is the international language. All other languages are dead, and with them many cultures.
Reconstructed: English is the official language. The other language(s) are used like Latin is in Real Life.
Plotted A Good Waste: To make communication between nations easier, France has made English a second official language. Everyone starts speaking English.
Played For Laughs: Alice decides to travel to France to improve her French. She is furious when everyone keeps speaking English.
Played For Drama: French is becoming a dead language, so people have turned to speaking English. Alice tries to make people realise the importance of their cultural heritage.