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Modal Verbs: 1.Modal verbs are used when we say that we expect things to happen or that things are possible,or necessary,or impossible,or improbable,or when we describe things that didn’t happen,or that we are not sure whether they happened. 2.Modal verbs have no -s on the third person singular.Questions and negatives are made without “do”. 3.Modal verbs have no infinitives. 4.Modal verbs have no past forms.“Could” and “would” are used with past meanings in some cases. 5.Modal verbs can be used with perfect infinitive to talk about things which didn’t happen,or which we’re not sure about. CStep Ⅲ Revision of the Important Usages of Modal Verbs T:Good work.As we all know,modal verbs can be classified into eight groups according to their usages.Today we will review some important usages of modal verbs.Firstly,let’s review the modal verbs that can be used to express “possibility”.Please tell me which modal verbs can be used to express “possibility”. Ss:Can/could/may/might all express “possibility”. T:When they express “possibility”,they are not quite the same.“Can” is used to talk about theoretical possibility.If we want to talk about the actual chances of something happening,or being true,we use “could/may/might”.Besides,“can” is sometimes used to talk about present “possibility”,but only in questions and negative sentences.Is that clear? Ss:Yes. T:Now,let’s do some exercises to master them better.Look at the screen and try to finish the sentences as soon as possible. (Teacher uses multimedia to show the sentences on the screen.) (责任编辑：admin) |