Modals of deduction and speculation

Finn Hello and welcome to 6 Minute Grammar with me Finn.

Catherine And me Catherine. In today’s programme we’re having a look at modal verbs.

Finn Now modal verbs are used in a lot of different ways but in this programme we’re looking at the modal verbs we use when we’re talking about things we think are possible or true - both in the present and in the past.

Catherine That’s right. When we don’t know something for sure, we often make guesses. And modal verbs can express how sure or unsure we are about our guesses. We’ll give you lots of examples…

Finn And we’ll check what you’ve learned in our quiz.

Catherine But first, we’re listening to Fiona, who is a science reporter. And Fiona is talking about some ancient fossils that were found in China and Taiwan.

Finn While you listen, think about this question: Are the fossils from humans?

INSERT Fiona The research teams analysing fossils found in China and Taiwan could be looking at something very important. It seems that the fossils can’t be from any known human species. They might be the result of breeding between species or they may belong to an unknown human species. The fossils suggest that before modern humans arrived in Asia, more diverse human groups may have lived there than previously thought.

Finn So that was Fiona. And we asked you: Are the fossils from humans?

Catherine And the answer is: Maybe. They might be the result of breeding between species or they may belong to an unknown human species.

Finn So we don’t know the answer for sure.

Catherine Exactly. Now the modal verbs might and may plus an infinitive show that we’re talking about a present possibility, not a certainty. The modal verb could does this too, either with an infinitive or with a continuous form. Here’s an example.

INSERT CLIP 1 The research teams analysing fossils found in China and Taiwan could be looking at something very important…

Finn In fact, we can say could be looking, might be looking or may be looking there.

Catherine That’s right: it’s a modal verb plus the continuous form of be plus verb -ing .

Finn But what about this sentence? Listen.

INSERT CLIP 2 It seems that the fossils can’t be from any known human species.

Catherine Fiona uses the modal can ‘t there. Now we use can’t with an infinitive when we believe strongly that something isn’t possible. The researchers believe strongly that the fossils don’t belong to any known human species. They can’t come from a known human species - it’s not possible.

Finn So they must be from an unknown human species.

Catherine That’s right. Must or can’t plus an infinitive both help us to express a strong belief that something is or isn’t possible.

Finn When we’re less sure about something, we can say, for example, the fossils might not, mightn ‘t or may not be from a known human species.

Catherine That’s right, but don’t use the negative couldn’t like this. It’s different. Couldn’t plus an infinitive means that something is completely impossible. Right then. Now let’s look at possibilities and certainties in the past. Here’s the next clip.

INSERT CLIP 3 The fossils suggest that before modern humans arrived in Asia, more diverse human groups may have lived there than previously thought.

Finn So we can also use might, may, could, can’t and must with have and the past participle of the verb when we think something was possible in the past.

Catherine Yes, we can say may have lived, might have lived or could have lived to express past possibility.

Finn And we use can’t or must with have and the past participle when we’re certain about something in the past. For example, t he scientists can’t have expected to find anything so important .

Catherine Exactly. They must have been very excited .

Finn I’m sure they were!

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6 Minute Grammar from BBC Learning English.

Finn And we’re talking about modal verbs.

Catherine And it’s quiz time! For each of these sentences, choose might , must or can ‘t to fill the gap: Number one: Finn, you got an A grade in physics? Wow. You have studied really hard.

Finn And the answer is must . You must have studied really hard. I did Catherine.

Catherine
Very good, Finn! Number two: Nick just called. He is stuck in traffic: he be late.

Finn
And this one is might . He might be late .

Catherine Well done! Number three: You have seen a ghost. There’s no such thing.

Finn And the answer is can’t. You can ‘t have seen a ghost. There’s no such thing. Is there Catherine?

Catherine I don’t think so, Finn. What about you?

Finn No.

Catherine We don’t believe in ghosts. And that’s the end of the quiz. I hope you got them all right.

Finn And there’s more about this at bbclearningenglish.com. Join us again soon for more 6 Minute Grammar.

Both Bye!