When making a case for something, you'll have an easier time convincing people that you're right if you start by asking questions. This will give you the chance to understand their points of view and strengthen your own. But not all questions are created equally. Know when to use what type of query:
Convergent: What, where, who, and when questions get a person to clarify what she is thinking. Use them when time is of the essence and you need specifics.
Divergent or expansive: Why and what if questions ask a person to expand on what he is thinking. Use them when you need someone to see the larger context of your argument.
Integrating: If...then what questions attempt to find common ground between opposing positions. Use them to build trust and encourage compromise, which is important when the stakes are high for both sides.
Source: Today's Management Tip was adapted from "To Have the Most Impact, Ask the Right Questions" by Chris Musselwhite and Tammie Plouffe.