We can ask God for anything. However, God doesn't always give us what we ask for because He knows our true motives and He knows what is best for each of us. While we might feel angry or disappointed when we don't get the answers for which we were hoping, we can be reassured that there is a reason for God's answer. He wants to see us prosper and do well. Sometimes He has to tell us "No!" in order for us to grow and become better for Him.
Have a question? Think about what you are asking and why you are asking it. Check your heart for your true motives, then don't be afraid to ask God...and don't be afraid of His answer! He only wants what is best for you!
Prayer:
Dear God-
Thank You for Your willingness to listen to all of my questions and pleas. Help me to accept Your answer, even when it doesn't match what I am hoping. Help me to accept Your plans for me and allow me to use Your answer for the betterment of myself and those around me. Through Jesus I pray, amen.