I put this on my main blog some years ago. Today I chiefly speak standard English but as a child growing up in South Wales I spoke a variant of what is sometimes known as Wenglish (ie English but with some influence from the Welsh language). We were not valleys Welsh so we spoke little real Wenglish but we heard it and spoke a little too. Most of the words below are in Wenglish dictionaries but not all. See here and here for more on that. Here is a list of words I was familiar with as a child but now rarely hear or use. In two cases I have used a Welsh 'w' which has a sort of 'ou' sound.
1. Cwpi down - to squat (cwpi down by 'ere a bit while we wait)
[We had a teacher in Secondary School called 'twti' presumably because, coming from elsewhere in Wales, he asked boys to twti down rather than cwpi down]
2. Scram - scratch (I'll scram yer eyes out you come near me)
3. Wisp - a stye (I think I've gorra wisp coming in me eye)
4. Daps - plimsolls (Miss said we've gorra bring daps today for PE)
5. Scag - snag (I just scagged my jumper)
6. Obstropolous - Obstrepereous (She was an obstropolous type, always causing trouble)
7. Ashcart - Refuse lorry (You'll end up working on the ashcarts if you don't buck up yer ideas)
8. Cwtch -To be fondled and snuggled up in an especially loving way (Come and have a cwtch with yer mam/dad)
9. Caibosh - messed up (That's put the caibosh on that then)
10. Dobber - ballbearing used as a marble ('E lost 'is 10-er dobber to a kid in Standard 4)
11. Conflab - long discussion or meeting (Come up about 11 and we'll have a good old conflab)
12. Ructions - big trouble (There'll be ructions if your father sees it like that)
13. Skewiff - Awry not straight (You've stuck it in the album all skewiff)
14. Tampin' - Angry ('E 'ad it on 'im, aye, when 'e realised. 'E was tampin')
15. Parched - Gasping for a cup of tea (Get that kettle on love, I'm parched)
16. Jibbons - spring onions (My dad used to like jibbons with his salad)