As an aside, if you drive into Wales via the M4 you'll see signs in Welsh and English, as required by law, but the first ones you see have English first. But the the further west, or inland, you go, more have Welsh first until that's the rule, reflecting local use of each language. The English only know or think of Wales as Cardiff and Newport and heavily populated South East areas. (Old Cardiffians make their own attempt at making English sound like a foreign language, but that's another matter!).
Even the English speakers retain some Welsh, without knowing it. The habit of adding 'isn't it' at the end of statements which aren't really questions is a direct translation of Welsh, and Welsh practice, into English. All they need now is to adopt the rest, which will not be easy. The discovery that nouns change their first letters according to where they lie, and so a dictionary is almost useless in looking up a word in a Welsh text, is only the first disheartening lesson. Still, the spelling is easy enough .