Use of Instrumental and Genitive Cases to Congratulate and Wish Something in Russian

Did you know why we use the Instrumental case when we wish a Happy New Year? It is because the verb “congratulate” (поздравлять-поздравить) is always used with the preposition с and the Instrumental case.  So, w say С Рождеством, С Новым Годом, с Днём Рождения, etc.

The verb “to wish” (желать-пожелать) is used with the Genitive case. So, when there is no verb, the Genitive case remains:

С Новым годом! Здоровья, успехов во всём! Happy New Year! Health and good luck in everything!