I don't fully agree with the example. The word "deceive" *means* to successfully cause someone else to believe something that's not true — not just to "try" to do this. E.g., American Heritage dictionary's definition of "deceive": ----- 1. To cause to believe what is not true; mislead. ----- Agreed that this may or may not be intentional. A couple of other flagrant but different examples of ambiguity in English are these: "I don't believe X" does *not* automatically mean "I believe X is false," and "I don't like X" does *not* automatically mean "I dislike X." But they are usually *used* that way, as if there are only two possibilities: *believing* or *disbelieving* something, and *liking* or *disliking* something. This quirk of English deceives many into thinking there are only two choices, that one must either believe or disbelieve everything, and that one must either like or dislike everything. I'm not sure if this is intentional on the part of English. —Dan Michael Greenwald wrote: ----- "X did not deceive Y" is ambiguous, by itself, as so many other English sentences are, because of different connotations of the word "deceive". It could (at least) mean: "X did not <successfully> deceive Y" or "X did not <intentionally> deceive Y". In the former X could have intended to, but was unsuccessful. In the latter X may have succeeded in deceiving Y, despite having no intention to deceive. -----