How about Peanuts where the adults all say “Wah, wahwah wah wah” (or " ’ ’ ’ ’ ’ "), because the kids aren’t supposed to understand them or at least they’re not listening?
Didn’t Hunt for Red October had this scenario? ISTR that the Russian characters start out speaking in subtitled Russian to set the scene, then switch to convenience English, then switch back to subtitled Russian. According to this, the end of the movie includes a scene where an American boards the sub, so the not-really-speaking-English Russians go back to subtitled Russian. But I haven’t seen the movie since it came out, all I remember is submarines and Sean Connery and the mixed use of subtitles along with just having the characters speak English.
As long as we’re on the subject, the 1983 remake of To Be or Not to Be started out with all of the characters speaking Polish (the movie is set in WWII-era Warsaw). After a couple of minutes of this, an offscreen narrator announces “Ladies and Gentlemen: In the interest of clarity and sanity, the rest of this movie will not be in Polish” and from that point on everyone speaks English.
In Judgment at Nuremberg, the courtroom scenes started with the German speakers speaking German, the English speakers speaking, English, etc. They made a point of everyone wearing headphones to hear the simultaneous translators, and it all looked and sounded authentic.
After a few minutes of this, while the lead defense attorney (Max von Sydow) is making an impassioned statement in German, the camera dramatically zooms in on him, and he suddenly starts speaking English. From that point on, all dialog is in English, but you conventionally understand that everyone is speaking their own tongue.
Very nicely done.
In Spain, there’s a popular series of movies from the 60’s starring a cute blond actress named Marisol. They are still frequently played on T.V. weekend afternoons. I came into one of these movies halfway and couldn’t understand why Marisol was pretending not to understand the rest of the cast and vice versa, when they were all speaking standard Castilian Spanish. My roommates explained that in this film, the spunky Marisol was attending a boarding school in England and great cultural hijinks were ensuing. This was conveyed by the actors doing occasional dramatic asides and saying, “Oh, these English people!” or “Oh, these Spanish people!” with great exasperation.
Wrong Max (Maximilian Schell)