posted by rfvv .
1. How is Ted special?
He dresses well.
2. Why is Ted special?
He is wearing a colorful shirt.
3. What is Ted's specialty?
He is wearing pink trousers.
4. What is special for Ted?
He is fashionable.
Which ones are grammatical and commonly used? Which ones are not suitable?
All are grammatically correct, but only 2 and 3 are commonly used.
4 doesn't mean the same thing as the others; this last question is asking what does Ted consider to be special, probably in someone else, not himself.