老师：Hello everyone, welcome to my class. Today we focus on the grammar study, the ing form. First, let's make clear of the learning objectives in this class. You will first revise the ing form as an adverb. You 2nd distinguish the ing form and a perfect ing form. And finally, try to use the ing form and a perfect ing form properly.
老师：And this is also the focus of this class. In the reading passage, we've Learned something about the writer's job as a volcanologist. It's really an exciting job. Right now I have two questions for you. 1, when did the writer start working as a volcanologist? To how does the radio feel about his or her work? If you are not sure about the answer, take out your textbook, tend to page 34 and find the answer in a textbook.
老师：Can we check now? I was appointed as a volcanologist working for the Hawaiian Volcano Observatory 20 years ago. 2. Have you studied volcanoes now? For many years? I'm still amazed at their beauty as well as their potential to cause great damage. Examine the sentences and tell in what way the structures are similar to each other and in what way they're different.
老师：Both of the sentences have the ing form working as the overview. The difference is in a second sentence, having started is the perfect ing form. We use the perfect ing form to refer to an action that took place before the time expressed by the name verb. That is to say, have you started, happened before? I'm still amazed. Well, in the first sentence, walking and I was appointed, the two actions are happening at the same time. Clear? Now, please open your textbook, underline the sentences from the reading passage with the perfect ing form.
老师：Can we check now? In these sentences, the perfect ing forms, happened before the main verbs? Help, went, didn't take, put on. Clear? Having made clear of the difference between the ing form and a perfect ing form, will do some practice now. Complete the sentences using the ng form or the perfect ing form, and tell the usages, can we check now?
老师：1. Coming out of my house, I saw the volcano erupting. From this sentence, we can see that the ing form can be used to refer to time. 2. Not knowing what to do, she turned to me for help. Here the ing form is used to express reason. 3, the children started for London, singing and laughing. Here the ing form is used to express manner. 4, the factory keeps giving off smoke, making the air dirty. Here the Ang form is used to express result.
老师：Let's check. Preparing fully, we can achieve great things. Here the ing form is used to express condition. 6. Though having lived in Canada for three years, he can't speak English well. Here the perfect ing form is used to express concession. Pay attention. Here we can use the ing form after conjunctions such as
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