I ran across a wonderful reminder in "The Little Red Writing Book" by Brandon Royal. In one chapter, Brandon talks about the importance of supporting what we say. If your teenager says to you, "I need the car tonight," you're likely to give him a furrowed brow, not a nodding head. The statement your teenager made is unsupported.  And a statement without support merits a denial without reason.

Businesses do this all the time. We say we provide excellent customer service (prove it). Or we say our products are all natural (list them). Or we say we care (tell me a story that demonstrates that).
 
What if your truth-telling teen says, "Your birthday is tomorrow and I haven't gotten you a present yet. I need the car tonight so I can go to the mall and shop for you." Now your head may nod. Now that's a statement with support that merits handing over your car keys.