一般来讲，分词或分词短语在句子中充当状语时，其逻辑主语与句子主语一致，如：Opening the drawer he took out a revolver．其中opening的逻辑主语是句子主语he。当分词的逻辑主语与句子的主语不一致时，则应将分词的逻辑主语补出来，如：George yawning，the conversation dropped．这种分词结构被称作独立主格结构。
但有时我们遇到这种情况：分词的主语既不与句子主语一致，分词本身又非独立主格结构，如：
Going up the hill，the statue of Lincoln struck my eye．在登上山的当儿，林肯的雕像十分引我注目。
Tired but happy，the bus whisked us home．我们虽然疲乏，但很高兴，公共汽车飞快地把我们送到了家。
这种分词在语法上被称作垂悬分词（dangling participle），也叫无依着分词。垂悬分词从起源上来说，是语言的错误使用（performance error），即将分词的主语与句子的主语错误联系，从而产生垂悬分词，所以有人又叫它错关联分词（misrelated participle）。
垂悬分词通常出现在句子开头或接近开头的位置，与句子中的其它成分不产生必要的句法关系，特别是它与句子主语无逻辑关系。鉴于这种特点，垂悬分词别名为：独立分词（absolute participle）或孤立分词（isolated participle）。
垂悬分词多数为现在分词，少数为过去分词。下文将从使用场合和情况对垂悬分词进行分类、归纳和总结。
1．当分词主语是不定人称时，如：
When dining in the restaurant，a jacket and tie are required．
2．当分词的主语是表示时间、天气、自然现象等的无人称代词it时，如：
Being Christmas，the government offices were closed．
3．当分词的暗含主语是句子的整体时，如：
The siren sounded，indicating that the air-raid was over．
Unknown to his closest advisers，he had secretly negotiated with an enemy emissary．
4．在正式科技文章中，分词前常常带有连词，其主语通常与I，we，you等同，如：
When installing a boiler，the floor space which is available is very important．
When treating patients with language retardation and deviation of languagedevelopment，the therapy consists，in part，of discus- sions of the patients'problems with patients and teachers，with subsequent language teaching carried out by them．
5．垂悬分词最常见于方式分离状语（style disjunct），表明说话人对所说的话的方式、条件以 及说话人的态度或看法，这种用法可细分为以下几种情况：
a．说话者用垂悬分词引出话题，如：talking of，getting back to，coming to等，意思为"谈 到……，关于……，回到……"等，请看例句：
Getting back to our story，the princess was killed．
Coming to this question，Isayno．
垂悬分词表明说话者的说话方式，如：putting it mildly，frankly speaking，generally speaking，roughly speaking，broadly speaking，biologically speaking等，请看例句：
Putting it mildly，you have caused us some inconvenience．
Generally speaking，dogs are more faithful to men than cats．
c．有些垂悬分词或词组表明说话的依据或视角，如：judging from，according to，considering，viewing it from，seeing，例如：
Judging from his expression，he is in a bad mood．
According to Barthes，the author had died．
Considering the low price，the car is worth buying．
d．有些垂悬分词或词组还为说话者所说内容的成立提供条件，如：providing（that）， provided（that），supposing，given，意思为"if或 with"，wanting和failing意思为"without"。例如：
Provided that a film entertains，few people care about its other merits．
Given prudence and patience，anybody can achieve something．
Supposing this to be true，he is certainly the murderer．
e．表示转折性的垂悬分词或词组有：admitting that，allowed that，allowing for，considering（that），assuming that，seeing that，granting that，granted that，notwithstanding，请看例句：
Allowing for（＝Considering）the deficiencies，the show is a success．
Granted（＝Granting）that you are right， you should not get angry．
Admitting（＝Assuming ＝Allowing）that he is drunk，that is no excuse．
f．有些垂悬分词或词组还可以表明说话者所说内容有无例外情况，如：barring，bating，excepting，excepted，saving that，意思为"除了……"；including，counting，settingaside， leaving．．．to one side，意思为"包括；除了……还有……"等，请看例句：
Barring（＝bating）this point，I agree with you．
There are fifteen students countingme．
Setting aside the question of capital，this business has many other problems．
从以上列举的垂悬分词，我们可以得到一个总体印象：垂悬分词虽然在产生之初为错误联系使用所致，但一旦被言语社团成员所接受，便成为正确英语；由于其产生的特殊性，及其使用场合的有限性，垂悬分词与一般分词相比灵活程度差一些，也就是说，垂悬分词的表达及用途相对固定。甚至于有些垂悬分词词组已被很多词典编撰者当作固定词组来看待，如上文中的generally speaking， frankly speaking，judging from ，com ing to details等。另外，从词性角度来看，有些垂悬分词已不再被看作是分词，失去了动词的本性，已演变成介词或连词。被当作介词看待的垂悬分词有：
considering，counting，including，barring，bating，excepting，excepted， concerning，regarding，respecting，touching， wanting，failing，pending，saving等等，例如：
Considering its cost，this machine is not worth buying．
He asked me questions concerning my health．
Pending a report from Rancy，we'll pro- ceed as planned．
- 考试辅导
