我理解：
串句：一句到底
破句：没头没脖
一、串句
（Run-on sentences）
串句是指在没有连接词或标点符号的情况下，将两个独立的单句串在一起。这种错句常使读者感到困惑，说不清哪里该起，哪里该止，有些是仅将两个单句用逗号隔开，犯了“逗号割裂”（comma splice)错误。修改串句的方法有：句号与大写；逗号与连接词；使用分号。例如：
（1）Reading is an important part of our lives it is hard to imagine it can be replaced.（2010.1）
应改为：Reading is an important part of our lives.It is hard to imagine it can be replaced./It is hard to imagine reading can be replaced as it is an important part of our lives.
（2）There is a very beautiful garden on campus，that is my favorite spot.（2009.10）
应改为：There is a very beautiful garden on campus，which is my favorite spot./ There is a very beautiful garden on campus.That is my favorite spot.
（3）Do your homework first，you may go out to play football.（2009.1）
应改为：Do your homework first.Then you may go out to play football.
（4）In summer，Juanna didn’t love traveling in Rome she felt it was too hot there.（2008.10）
应改为：In summer，Juanna didn’t love traveling in Rome.She felt it was too hot there./In summer，Juanna didn’t love traveling in Rome because she felt it was too hot there.
（5）I am very tired this evening，it was a long day at the office.（2008.1）
应改为：I am very tired this evening.It was a long day at the office./ I am very tired this evening after a long day at the office.
二、破句（Fragmentary sentences）
要表达一个完整的意思，每个句子都必须有主语和谓语动词。有些所谓的句子，或无主语，或无谓语动词，仅仅是单词的堆砌，在语法上是讲不通的，而且语义也不完整。修改方法有：把破句附属于其前或其后的一个主句或去掉这个从属连词；把现在分词改成动词的正确形式；给破句加上主语和动词，使其成为一个完整的句子；改变必要的词使破句成为它前面句子的一部分。例如：
（1）Before the widespread use of the Internet.There was no universal way to download new reading materials.（2010.1）
应改为：Before the widespread use of the Internet，there was no universal way to download new reading materials.
（2）Without low-cost transportation.Millions of Africans have a long walk to their destinations.（2010.1）
应改为：Without low-cost transportation，millions of Africans have a long walk to their destinations.
（3）She closed her eyes.Thinking back through the years of being mother，wife，friend，daughter，and sister.（2009.10）
应改为：She closed her eyes，thinking back through the years of being mother，wife，friend，daughter，and sister.
（4）I could not help looking back at him.Tears streaming down my face.（2009.1）
应改为：I could not help looking back at him，tears streaming down my face.
（5）One of Jenny’s greatest joys in life is eating desserts.Such as milkshake，cookies or strawberry cake.（2008.10）
应改为：One of Jenny’s greatest joys in life is eating desserts such as milkshake，cookies or strawberry cake.
（6）A very powerful story that really puts its message across.（2008.1）
应改为：It is a very powerful story that really puts its message across.