"I must drink."

Translation: Mae'n rhaid i fi yfed.

[EAML48]

Is the "yn, 'n" normal after the "mae"? I have never seen it, nor have I seen "yn" in any of the other tenses, for example: "Bydd rhaid i fi fynd", not, "Bydd yn rhaid i fi fynd."

[EllisVaughan]

I only use the "mae'n" variant. It might not be common (maybe even old-fashioned).