Can I replace "think with" with "think about" or "think on"? I want to know how to use "think with".
Unfortunately, "thinking with" can not be replaced with "think about" or "think on". "Thinking with" is an informal phrase that means "chose/chooses". You can think of this sentence as "I just don't know why she chooses the dry food." Therefore, you can use "thinking with" to express someone else's choice in an informal way. Keep in mind, "thinking with" has a negative connotation because it usually describes a "bad choice". Ex: I don't know what she was thinking with that new hair color, it doesn't suit her. Ex: What were you thinking with this couch, I don't like it.