Two at once

Herb here makes an innocent observation, in the course of which he manages two significant violations, so that it's no wonder Sarah misunderstands him.


First, he violates one of the Gricean Maxims, that of Quantity: Make your contribution as informative as is required (for the current purposes of the exchange), and Do not make your contribution more informative than is required. There's absolutely no reason for her to know what color the thread is; it's not like she walks around with red or purple threads in her hair.

Second, having decided to provide her with the extra information, he puts the modifier in the wrong place: "a gray piece of thread"? Not "a piece of gray thread"?

And now he'll pretend he didn't do it on purpose to pay her back for winning the argument yesterday...