Usage patterns
〈人〉がかわいそうsomeone/something is pitiable, poor thing
The child crying alone was pitiful.
〈人〉をかわいそうに思うto feel sorry for someone
Feeling sorry for her, I spoke to her.
かわいそうな〈人〉a pitiful/poor (person, animal, etc.)
That dog was a poor abandoned animal.
〈事〉でかわいそうpitiful because of ~
I want to help the children who are suffering from illness.