插入句 在句中和句尾, 用以补充说明或加强印象 1) 字的插入 1. His son, fortunately, was rescued from the burning house. Fortunately, his son was rescued from the burning house. 2. She is, undoubtedly, an able secretary. Undoubtedly, she is an able secretary. 3. She was very tired, nevertheless, she went to work as usual. 连接副词,然而 字的插入以不影响句子结构,语句通畅为前提, 比如不能破坏was rescued (be p.p.) 2) 片语插入 1. It is, after all, due to his misunderstanding. After all, it is due to his misunderstanding. 2. Clothes in this boutique, in my opinion, are overpriced. 3. He’s rude, bad-tempered and conceited — in short, he’s a very unpleasant man. 4. She seldom, if ever, goes to the movies by herself. 就是有也很少 5. It was cold, and what was worse / to make matters worse, it began to rain. 3) 子句的插入 1. I thought he would get better, but as it is, he is getting worse. 但是事实上 2. He is, as it were / so to speak, a walking dictionary. 所谓的 明明是it 作词却用were 动词，类似于假设，实际上他并不是字典，与现在事实相反用过去式。 3. Fishing in this river, as far as I know, is prohibited. 就我所知 4. Something ought to be done, I agree. It’s worth thinking about. 5. Too much exercise, I think, is bad for your health. I think (that) too much exercise is bad for your health. 6. Picasso, as you know, is one of the greatest artists in the world. 本文来源：https://www.wddqw.com/doc/b074940182d049649b6648d7c1c708a1284a0ab8.html