So did you get anything from the above picture :) ?
There are broad range of questions which can be asked in the requirements gathering sessions to understand the Business Requirements clearly. With the help of all these "What", "Why", "When", "How", "Where" and "Who" related questions you can collect clear requirements from your Stakeholders.
Note: The Questions listed in each of the Categories in the above image are just sample Questions. You can frame your own questions relevant to your Project.
One more tips for you guys: While eliciting and documenting the requirements, always make sure that all the Requirements follow the SMART Rule. Refer the below picture for more details.
Though this is one of the basic posts related to Business Analysis Concepts, I hope it would help you all in your future work.
As We Work...We Learn...