新概念英语第二册第57课

新概念英语第二册第57课
Lesson 57 in the New Concept English Book 2 introduces the use of the modal verb "must" to express logical deduction or certainty.
The lesson begins by explaining that 'must' is used when the speaker is certain about something because there is strong evidence or logical reasoning. For example, if we see dark clouds, we might say, "It must rain soon." In this case, we are not guessing; we are certain based on the evidence of dark clouds.
The example demonstrates that we use 'must' to talk about the present or future. However, for the past, we use 'must have.' For instance, if we see someone coming in with a wet umbrella, we might remark, "It must have rained." Again, this deduction is based on a certain piece of evidence.
The lesson further explains that if we think something is not possible, we use 'can't.' For instance, if we arrive at a bus stop and the bus has already left, we might say, "The bus can't still be here," implying that the bus has already left and it's impossible for it to still be there.
The text also provides additional examples using 'must' and 'can't' for different situations. It discusses logical deductions such as a doctor telling a patient that they must rest, a car not starting because the battery is flat, and a small child unable to reach things on a high shelf.
In conclusion, Lesson 57 emphasizes the use of 'must' and 'can't' to express logical deductions or certainty in English. These modal verbs are used to convey strong evidence or
logical reasoning regarding a particular situation in the present, future, or past.。