Questions & Answers about Я желаю вам счастья.
Why is "happiness" in the Genitive case (счастья) instead of the Accusative?
The verb желать (to wish) is a verb of desire. In Russian, verbs expressing desire, expectation, or fear often require their target object to be in the Genitive case rather than the Accusative. This is especially true for abstract concepts like happiness.
Why use the Dative case вам instead of the Accusative вас?
Вам is the indirect object here. You are directing your wish to someone. Just like giving a gift or telling a story, wishing something to a person requires the Dative case.
What is the dictionary form of счастья and how does its ending change here?
The dictionary (Nominative) form is счастье, which is a neuter noun. To form the Genitive case, the final -е changes to -я, resulting in счастья.
Would I ever use the Accusative case with the verb желать?
It's rare but possible. Verbs of desire can sometimes take the Accusative case if you want a very specific, concrete object (like a specific physical item). However, when making conventional wishes for abstract things—like happiness, health, or good luck—you must always use the Genitive case.