Breakdown of Worüber ist die Enttäuschung so groß?
sein
to be
groß
big / tall
so
so, such (intensifier)
worüber
what about
Questions & Answers about Worüber ist die Enttäuschung so groß?
Why does this sentence start with worüber instead of just asking über was?
The noun die Enttäuschung (the disappointment) has a fixed partnership with the preposition über (about/over). In standard German, when asking a question about a thing or concept using a preposition, we form a wo- compound. Because über starts with a vowel, we add an -r- for pronunciation, creating worüber. While you might hear über was in casual speech, worüber is the grammatically correct standard.
If I answer this question and state what the disappointment is about, what case do I use after über?
You must use the accusative case. Although über is a two-way preposition that sometimes takes the dative for physical locations, when it acts as a fixed preposition for abstract ideas (like emotions or conversations), it almost always requires the accusative. For example, you would answer: Die Enttäuschung über den neuen Chef (The disappointment over the new boss).
How would this question change if the disappointment was about a person instead of a thing?
You cannot use wo- compounds like worüber for living beings. To ask about a person, you must keep the preposition separate and use the question word for "who" in the correct case. Since Enttäuschung über demands the accusative, the question becomes: Über wen ist die Enttäuschung so groß? (Over whom is the disappointment so great?).
Does the verb enttäuschen (to disappoint) take the same fixed preposition as the noun?