1.
Negative: She isn't sitting on a wooden chair
Yes/Now question: Is she sitting on a wooden chair?
WH-Question: Who is sitting on a wooden chair?
2.
Negative: She isn't holding a coat
Yes/Now question: Is she holding a coat?
WH-Question: What she is holding?
3.
Negative: He isn't wearing dark clothes
Yes/Now question: Is he wearing dark clothes?
WH-Question: Why he is wearing dark clothes?