Formal:
* Byddwch chi'n cael eich colli. (Literally: "You will be missed.")
* Byddwch chi'n golli'n fawr. (Literally: "You will be missed greatly.")
Informal:
* Fe'ch colliwn ni. (Literally: "We will miss you.")
* Mi fyddwch chi'n cael eich colli'n fawr. (Literally: "You will be missed greatly.")
More affectionate:
* Byddwch chi'n cael eich colli'n fawr iawn. (Literally: "You will be missed very much.")
* Fe'ch cariwn ni'n fawr iawn a byddwch chi'n cael eich colli. (Literally: "We love you very much and you will be missed.")
Note: The Welsh language has a few different ways to express the future tense, so you may see different variations of these phrases.