Goodbye! I will miss you!" in Welsh is "Hwyl fawr! Byddaf yn dy golli di!"
meth, pall (noun) Miss methu, pallu, colli (verb)
I miss you loads in Welsh is "Rwy'n dy golli di llawer!"
A formal goodbye is "da boch chi", meaning good be with you. A less formal way to say this is "hwyl", or you can simply say ta-ta or ta-ra.
Goodbye: there are several ways of saying this. "Da bo ti" (familiar) and "Da bo chi" (formal) are the usual ones. There is also "ffarwel", which to be honest I have only ever seen in print. If you...
Caru ti a methu ti