abbr.(省略词): A.D., A.M., B.C., e.g., etc., FBI, fob, i.e.

prep.(介词): aboard, about, above, across, after, against, along, alongside, amid, amidst, among, around, as, at, before, behind, below, beneath, beside, besides, between, beyond, both, but, by, concerning, despite, down, during, ex, except, for, from, in, inside, into, like, minus, near, nearby, notwithstanding, of, off, on, onto, opposite, outside, over, past, per, plus, regarding, round, since, through, throughout, till, to, toward, under, underneath, unless, unlike, until, up, upon, versus, via, with, within, without

int.(感叹词): alas, damn, dear, farewell, good-bye, goodness, hello, hey, hi, hurrah, hush, oh, thank, thanks, welcome, well, why

pron.(代词): all, another, anybody, anyone, anything, each, either, everybody, everyone, everything, first, former, he, her, herself, him, himself, his, I, it, its, itself, many, me, mine, my, myself, neither, nobody, none, one, oneself, other, our, ourselves, same, she, some, somebody, someone, something, such, that, their, them, themselves, these, they, this, those, us, we, what, whatever, when, whence, where, which, whichever, who, whoever, whom, whose, you, your, yourself

conj.(连词): although, and, as, because, but, for, however, if, lest, nor, notwithstanding, once, only, or, otherwise, provided, since, so, suppose, supposing, than, therefore, though, unless, until, when, whence, whenever, where, whereas, wherever, whether, while, whilst, why, yet

num.(数词): billion, eight, eighteen, eighth, eighty, eleven, eleventh, fifteen, fifth, fifty, five, forty, four, fourteen, fourth, hundred, hundredth, million, nine, nineteen, ninety, ninth, one, seven, seventeen, seventh, seventy, six, sixteen, sixth, sixty, ten, tenth, third, thirteen, thirty, thousand, three, twelfth, twelve, twentieth, twenty, two, zero

aux.(情态动词): can, do, may, must, need, ought, shall, should, will