such is the fate of hapless lexicography, that not only darkness, but light, impedes and distresses it; things may be not only too little, but too much known, to be happily illustrated.  To explain, requires the use of terms less abstruse than that which is to be explained, and such terms cannot always be found; for as nothing can be proved but by supposing something intuitively known, and evident without proof, so nothing can be defined but by the use of words too plain to admit a definition.

Other words there are, of which the sense is too subtle and evanescent to be fixed in a paraphrase; such are all those which are by the grammarians termed expletives, and, in dead languages, are suffered to pass for empty sounds, of no other use than to fill a verse, or to modulate a period, but which are easily perceived in living tongues to have power and emphasis, though it be sometimes such as no other form of expression can convey.

My labour has likewise been much increased by a class of verbs too frequent in the English language, of which the signification is so loose and general, the use so vague and indeterminate, and the senses detorted so widely from the first idea, that it is hard to trace them through the maze of variation, to catch them on the brink of utter inanity, to circumscribe them by any limitations, or interpret them by any words of distinct and settled meaning; such are bear, break, come, cast, full, get, give, do, put, set, go, run, make, take, turn, throw.  If of these the whole power is not accurately delivered, it must be remembered, that while our language is yet living, and variable by the caprice of every one that speaks it, these words are hourly shifting their relations, and can no more be ascertained in a dictionary, than a grove, in the agitation of a storm, can be accurately delineated from its picture in the water.

The particles are among all nations applied with so great latitude, that they are not easily reducible under any regular scheme of explication:  this difficulty is not less, nor perhaps greater, in English, than in other languages.  I have laboured them with diligence, I hope with success; such at least as can be expected in a task, which no man, however learned or sagacious, has yet been able to perform.

Some words there are which I cannot explain, because I do not understand them; these might have been omitted very often with little inconvenience, but I would not so far indulge my vanity as to decline this confession:  for when Tully owns himself ignorant whether lessus, in the twelve tables, means a funeral song, or mourning garment; and Aristotle doubts whether [word in Greek] in the Iliad, signifies a mule, or muleteer, I may surely, without shame, leave some obscurities to happier industry, or future information.