These five examples are not used in English. They would only be "correct" (pronounced as "summat") in non-standard regional speech. For example:
A: Kin you read this to me?
B: Hmm, it is summat not easy, but I think I can.
A: You kin read. This should be easy for you.
B: It is not summat easy, but I think I can do it.
B: I thought I could read it, but it