Complex sentence: "Theaetetus is flying" is false while "Theaetetus is sitting" is true, because the predicate "flying" is different from the actual predicate of Theaetetus, which is "sitting".
Split into simpler sentences: Theaetetus is flying "is false while"Theaetetus is sitting " "is true. Because the predicate "flying"is different from the actual predicate of Theaetetus, which is "sitting".