简述：

run-on: 完整句子A, 完整句子B.

   两个完整句子之间没有连词（and, or ...)连接。却用了逗号等表示句子没有结束的符号。

sentence fragment: 句子结构不完整。常见的是只有主语，没有谓语和宾语。

dangling modifier: 修饰对象不明。常说分词短语的。

Run-on Sentences 连写句

When a sentence consists of more than one clause, those clauses must be joined properly. It is never acceptable to hook two clauses together with a comma, as the "sentence" below does. That's called a run on sentence.

连写句：（错用逗号等）使两个或多个独立从句不正确地连在一起的句子

Wrong:        Nietzsche moved to Basel in 1869, he planned to teach classical philology.

There are a number of acceptable ways to fix a run on.

     1.  Make two separate sentences:

          Nietzsche moved to Basel in 1869. He planned to teach classical philology.

     2a. Change the comma to a semicolon:

          Nietzsche moved to Basel in 1869; he planned to teach classical philology.

     2b. Join the clauses with a semicolon and a transition word such as however or therefore.

          Nietzsche planned to teach classical philology; therefore, he moved to Basel in 1869.

Sentence Fragments 句子（成分）残缺

Every sentence must contain at least one complete independent clause. If there is no independent clause at all, or if what's supposed to be the independent clause is incomplete, you've got a sentence fragment.

句子残缺：句子成分不完整，缺少一个完整的独立分句。

Wrong:        While many people, who have worked hard for many years, have not managed to save any money, although they are trying to be more frugal now.

This sentence fragment consists of nothing but subordinate clauses. One of the subordinate clauses must be made into an independent clause.

Correct:        Most people, who have worked hard for many years, have not managed to save any money, although they are trying to be more frugal now.

Also Correct:   While most people, who have worked hard for maw years, have not managed to save any money, they are trying to be more frugal now.

dangling modifier摇摆修饰

修饰对象不明确