a. additive: and, or, also, in addition, furthermore, besides, similarly, likewise, by contrast, for instance;
b. adversative: but, yet, however, instead, on the other hand, nevertheless, at any rate, as a matter of fact;
c. causal: so, consequently, it follows, for, because, under the circumstances, for this reason;
d. temporal: then, next, after that, on another occasion, in conclusion, an hour later, finally, at last;
e. continuatives: now, of course, well, anyway, surely, after all.