Western about language, anyone?

This is a Western film my dad said that he saw back in the eighties. It was about a couple of guys coming to a Mexican farmer and saying that he stole a couple of horses. He’s innocent and tries to tell them that but they think he’s lying and he get’s gunned down. Since he was a Mexican he spoke different and they didn’t understand him and the film ended with that a schoolteacher understood what’s happened and told everybody. Would be interesting to know what the film is called, it’s propably American but I can’t think of any better place than this ;).

Might be the Ballad of Gregorio Cortez?

Yes, that’s the one. Thanks a lot!