What Did I Just Say!?! How New Insights into Childhood Thinking Can Help You Communicate More Effectively with Your Child (Henry Holt and Co) by Denis Donovan and Deborah McIntyre.
Some amusing and clever insights into how parents' "politically correct" language gets in the way of being an effective parent with children. However, the book doesn't go beyond the "linguistics" for the reasons why parents do "parentsspeak" these days and why their kids don't listen (see The War Against Boys).