Formal:
* Rwy'n caru nain: This is the most literal and formal translation, using the verb "cariad" (love) in the present tense.
Informal:
* Dw i'n caru nain: This is a more informal and casual way of saying it, using the contracted form "Dw i" for "I."
* Rwy'n hoffi nain: This translates to "I like nan," which is a more informal and less intense expression of love.
Using a diminutive:
* Rwy'n caru nain fach: This translates to "I love little nan" and adds a touch of affection.
You can also use other expressions depending on the context and your relationship with your nan. For example:
* Rwy'n caru ti'n fawr, nain: This translates to "I love you very much, nan."
* Rwy'n dy garu'n fawr, nain: This translates to "I love you a lot, nan."
Ultimately, the best translation will depend on your personal preference and the situation.