This is very hard to explain. Essentially, it's used to point out how useless a particular object or action is. If you say something like: "अमेरिका जा भी पाया तो वहाँ क्या उखाड़ लेगा?"-"amerika ja bhi payega to vaha kya ukkhad lega?", meaning, "Even if you're able to go to America, what great thing will happen there?" As in "What difference will it make?", "What sort of great achievement will you get?" Do you get the idea here? EDIT: Just realized the it's/its mistake here, but can't edit title.