Rice's theorem: Any nontrivial property about the language recognized by a Turing machine is undecidable.
I know the proof but I am not able to understand the theorem. I think trivial properties are like :language recognised by Turing machine contain at substring "aab". where as nontrivial property means is language accepted by Turing machine is finite etc.
My question : Give at least two example of trivial properties and two non-trivial property about the language recognized by a Turing machine.