My latest reader response for The New York Times Magazine's On Language column tackles a turn of phrase that has come up on Language Log many times: cannot be underestimated. The occasion is New York Gov. Andrew M. Cuomo's inaugural address earlier this month, in which the governor used the magic phrase twice (and talked about "underestimating" a third time without the cannot). I give the requisite shout-out to Language Log, of course.
There are opposing schools of thought for why “cannot be underestimated” almost always gets used in this topsy-turvy fashion. Mark Liberman, a linguist at the University of Pennsylvania who writes for the group blog Language Log (to which I also contribute), chalks up the problem to the inability of our “poor monkey brains” to handle multiple negatives properly. Similar “overnegation” can be found in such phrases as “I miss not having you around” (meaning “I miss having you around”) and “I never fail to miss an opportunity” (meaning “I never miss an opportunity”). Liberman sees such examples as evidence of an overall “temptation of overnegation” in English usage.
Really, it was just an excuse to work a reference to our "poor monkey brains" into The Times. You can read the whole thing here, and see Mark's master list of posts for further discussion on this and related misnegations.