Welsh evolved from 'British' around the C4th AD and in the C6th Welsh was widely spoken from southern Scotland all the way down through all of modern England but is only found mostly in Wales today.
Most Welsh people blame the coming of the English for its decline but really only have their own materialistic brothers and sisters to blame really. That and their immense parochialsm. Welsh people tend to blame the English for everything except when they prefer to blame the valley next door first. All this helps them avoid the responsibility of running their own country themselves and being a success. They prefer to be shy, polite failures who don't upset anyone.
The Welsh language lends itself to metaphor and poetry. It is wonderfully concise and expressive when used by those who know it well.
More and more Welsh speakers are learners. They speak it well sometimes but many fear Welsh as it is spoken by many is quickly becoming nothing but a translation of English. They have a point. Welsh idiom is rooted in rural agricultural society and is a bit outdated. Welsh needs new idioms for its new urban speakers. Instead it seems to steal them from English.
The future of Welsh may rely on this challenge.
All Welsh speakers in Wales are now bilingual with English as their co-language.
Do you speak Welsh?
Ydw. Iaith y nefoedd! (udoo. yaith uh nev-oeth)
Yep! The language of heaven.
IDIOM: Mae hi'n bwrw hen wragedd a ffyn
(mine boo-roo hen rag-eth a fin)
It's raining cats and dogs (lit. It's throwing old women and sticks)