CalifJim wrote: 3. Fine. a goes with interview, not with the date. The date is used as an adjective to interview. It specifies which interview. The meaning is therefore: In an interview with Der Spiegel on May 30, 2006 ... CJ
CalifJim wrote: The correct way to ask the question is What role does the date play here? (What role the date plays here? is not correct.) CJ
What role the date plays here?
There is no operator in the sentence.
To form interrogatives, place the operator before the subject
He is nice
Is he nice?
The date plays an important role here.
What kind of role does the date play.