Two uses sit under this shape. Most lines have 뭔가 'something' before 사다: 뭔가 사고 싶긴 한데, 'I do want to buy something'. In the others, -인가 follows a time or place and turns it into a hedge — 작년인가 샀거든요 'I bought it last year, I think', 밤 10시인가 사서 'bought them around ten at night', 필리핀 어디선가 산 거야 'bought somewhere in the Philippines'.