Very Easy
and, but, so, because, or, then, also, too, as well, if, before, after, when, while, like
Easy
although, though, since, still, yet, again, besides, first, next, last, finally, later, now, here, there
Easy-Medium
however, therefore, thus, because of, as a result, for example, for instance, such as, in fact, really, very, even, even
though, in addition, moreover
Medium
furthermore, on the other hand, in the same way, similarly, as, unless, if not, provided that, due to, that’s why, at last,
after that, at first, step by step, in general
Medium-Advanced
in conclusion, to sum up, overall, in short, in brief, meanwhile, otherwise, instead, rather, even if, as soon as, as long
as, in spite of, despite, according to
Advanced
nevertheless, nonetheless, consequently, hence, thereby, whereas, while (contrast), not only…but also, whether…or,
on the contrary, in contrast, by contrast, to clarify, to illustrate, in other words, above all, after all, as far as, as well as,
regardless of
