I know how to say I’ve/you’ve/etc got something as in mae car da fi but if you want to use possession in a sentence like ‘where is my/your/etc dog?’ what would be the various structures?
Ble mae… Where is…
Fy nghi (i)…my dog
Dy gi (di)…your dog (singular familiar)
Ei gi (f/e/o)…his dog
Ei chi (hi)…her dog
Ein ci (ni)…our
Eich ci (chi)…your (plural/ formal)
Eu ci (nhw)…their
At the risk of upsetting the purists, and if you don’t mind sounding like you’re nineteen, ci fi, ci ti, ci fe/fo etc works fine in informal situations.
How do you mean “sounding like you’re 19” ? Is that a more slangy thing that young people use?
Yep. Spot on.