1）句子意思表达不完整 × The lecture was given in such an interersting way. √ The lecture was given in such an inereresting way that everyone enjoyed it very much. 2）句子的主从关系模糊 × We are going to visit John, and he is our English friend. √ We are going to visit John who is our English friend. 3) 连接词使用不当 × The main reason he was absent was because he was ill. √ The main reason he was absent was that he was ill. 4) 主谓不一致 × Every teacher and student were invited to go to the party. √ Every teacher and student was invited to go to the party. 5) 中心不明白 × I was watching a film last night, I suddenly found Mary sitting in front of me. √ When I was watching a film last night, I suddenly found Mary sitting in front of me.