For all its apparent difficulty to English eyes, Welsh spelling is pretty logical, and the pronunciation is directly related to the letters you see. It's almost 100% phonetic, and far more so than English, for example.
Irish spelling - nope. To someone not brought up there, the relation between spelling and pronunciation is often almost comically indirect. I have been collecting a few examples for the amusement and edification of chums, but last night I saw one that takes not only the biscuit, but the whole McVities factory.
You could never have guessed that. Unless you were Irish, of course.