9. What ... she (wear) when you (see) her at the party?

{"english_answer"=>"What was she wearing when you saw her at the party?", "explanation"=>"The first action needs past continuous tense to indicate that it was in progress at the time of the second action. The verb 'wear' should be in past continuous tense 'was wearing' and the verb 'see' should be in simple past 'saw'."}