Complex sentence: In the film's opening scene, Harmonica kills three men sent by Frank to kill him, and, in a roadhouse on the way to Sweetwater, he informs Cheyenne that the three gunfighters he killed appeared to be posing as Cheyenne's men.
Split into simpler sentences: In the film's opening scene, Harmonica kills three men sent by Frank to kill him. In a roadhouse on the way to Sweetwater, he informs Cheyenne that the three gunfighters appeared to be posing as Cheyenne's men.