▲程度副词是个很大的集合，个人认为要想试图完全归纳需要极大的工作量。

所以我也只是尽量提供一下手头资料帮归纳好的结论，并进行适当地甄别和融合，权当对其他老师答案的补充。

▲程度副词是对一系列语义上可以表示程度高低的副词的总称。

它们主要有两个功能：

1.在形容词短语和副词短语中充当修饰语（程度修饰语）。

2.在句子中充当强化语（程度状语）。

▲副词充当形容词/副词短语内的程度修饰语（degree modifier）：

1.带 -ly 后缀的程度副词

absolutely, amazingly, awfully, barely, completely, considerably, dreadfully, easily, enormously, entirely, exceedingly, excessively, extensively, extremely, fairly, fantastically, fully, greatly, hardly, highly, hugely, immensely, incredibly, infinitely, intensely, largely, moderately, nearly, noticeably, partly, perfectly, positively, practically, profoundly, purely, really, reasonably, relatively, remarkably, simply, slightly, strikingly, strongly, sufficiently, supremely, suspiciously, terribly, totally, tremendously, truly, unbelievably, utterly, virtually, wonderfully

2.不带 -ly 后缀的程度副词

about, almost, altogether, as, bloddy, damn, dead, downright, even, extra, far, how, however, indeed, jolly, just, least, less, mighty, more, most, not, outright, plain, pretty, quite, rather, real, so, somewhat, still, too, very, way, well, yet

◆有趣的是，有一系列有同形形容词的程度副词都属于非正式用法，可以参考我在这个问题里的解答：http://ask.yygrammar.com/q-6016.html

▲强化语（intensifier）可以根据程度进行分类。

为提供更多信息，我把副词以外的强化语也一并列出。

1.最高程度（maximal）

副词：absolutely, altogether, completely, entirely, extremely, fully, perfectly, quite, thoroughly, totally, utterly, wholly

介词短语：in all respects

2.较高程度（multal）

副词：badly, bitterly, deeply, enormously, far, greatly, heartily, ighly, how, immensely, intensely, largely, particularly, profoundly, severely, so, strongly, terribly, tremendously, vastly, violently, well

限定词：much

名词短语：a great deal, a good deal, a lot

介词短语：by far, for the most part

3.中间程度（moderate）

副词：but, just, merely, mildly, moderately, only, partially, partly, quite, rather, simply, somewhat

介词短语：in part, in some respects, to some extent

4.较低程度（paucal）

副词：slightly

限定词：a little, little

名词短语：a bit

5.最低程度（minimal）

副词：barely, hardly, scarcely

介词短语：at all, in the least, in the slightest

成语：so much as

6.近似程度（approximating）

副词：almost, nearly, practically, virtually

成语：as good as, all but, kind of, more or less, sort of

7.相对程度（relative）

副词：sufficiently

限定词：enough, less/least, more/most

限定词短语：too much

8.此外，强调语（emphasizer）在强调可分等级的成分时，可以起强化语的作用，表示较高或最高程度。

副词：actually, certainly, clearly, definitely, indeed, obviously, plainly, really, surely

介词短语：for certain, for sure, of course

▲参考资料：

《英语语法大全》（CGEL） p583-585, p589-591, p597-599, p445

《剑桥英语语法》（CaGEL） p583-585, p721-724