彼女の結婚式はいつですか。

she; her; her; girlfriend; sweetheart

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question

marriage ceremony; wedding; nuptials

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

to need; to want

indicates two contrasting actions; indicates possessive (often found in place names and compound words)

be; is

indicates a question (sometimes rhetorical); or; whether or not; some- (e.g. something, someone); indicates doubt, uncertainty, etc.; emphatic prefix; suffix forming adjectives or adverbs; in that way