Welsh

This is a question for native British English speakers. Sometimes when I am flicking thorugh the TV channels, I stop on the Welsh channel for a while, just out of interest to listen to it. Although I hardly understand any of it (unless they use an English word), I am always struck by the feeling that it is not a foreign language in the same way other languages are. Even though if I listened to a language such as French or Spanish, I would undertsand more, I still feel there is something more foreign about them. But with Welsh I almost feel that they are speaking a form of English, I just can't quite pick up on it. I know this is obviously not the case, and Welsh is in fact relatively far removed from English, so I wonder why it is. I suppose it is the fact that they are British and so other national trais such as certain gestures do remain the same. But I think there is also something about intonation as well, something about it does seem like English

Probably because They speak Welsh with an English accent and intonation, but I have no clue.....
the same happens to me when I listen to Catalan. It reminds me of Spanish intonation and pronunciation. I know that Catalan and Spanish belong to the same group of languages but they have something familiar that, for instance, Spanish and Portuguese don't have

Also, the close proximity of the two languages with speakers going both ways over centuries would have undoubtedly created a Sprachraum effect.

Perhaps they also "look" like your countrymen (one of us) to your mind. Perhaps the gestures and facial expressions look familiar.