Informal:
* Cael prynhawn da! (pronounced: kai pryn-houn dah) - This is a simple and friendly way to wish someone a good afternoon.
* Mwynhew dy brynhawn! (pronounced: mwyn-hew dih pryn-houn) - This translates to "Enjoy your afternoon!" and is a bit more expressive.
Formal:
* Gobeithio y bydd gennych brynhawn da. (pronounced: go-bay-thee-oh eh vith gen-ich pryn-houn dah) - This is a more formal way to say "I hope you have a good afternoon."
Remember that Welsh pronunciation can be tricky. You can find helpful pronunciation guides online or with a Welsh speaker to help you get the hang of it!