speculate speculate = to guess about the possible causes or effects of something without knowing all...
DESCRIPTION
must must + infinitive It’s 2 pm. Peter hasn’t eaten since 6 am. What can we deduce? HUNGRY must feel He must feel hungry. mustsure is We use must because we are sure something is true.TRANSCRIPT
Speculate
speculate = to guess about the possible causes or effects of something without
knowing all the facts or details
Speculating about the present
must + infinitive
• It’s 2 pm. Peter hasn’t eaten since 6 am.• What can we deduce?• HUNGRY• He must feel hungry.• We use must because we are sure something
is true.
may / might / could + infinitive
• Mary is absent today.• What can we deduce?• ILL• She may / might / could be ill.• We use may / might / could because maybe it
is true.
may not + infinitive
• I’m not sure whether I can lend you any money.
• What can we deduce?• HAVE ENOUGH• I may not have enough.• We use may not because maybe it is not true.
can’t + infinitive
• He has just eaten 6 hamburgers!• What can we deduce?• HUNGRY• He can’t be hungry.• We use can’t because we are almost sure it is
not true.
Why is the baby crying?
hungry
She must be hungry.
Why is the baby crying?
happy
She can’t be happy.
Why is the baby crying?
spoiled
She may / might / could be spoiled.
Why is the student sleeping in class?
tired
He must be tired.
Why is the student sleeping in class?
the class / boring
The class may / might /could be boring.
Why is the student sleeping in class?
Teresa / his teacher
Teresa can’t be his teacher.
Why are the students so happy?
Teresa / their teacher
Teresa must be their teacher.
Why are the students so happy?
English class now
They may / might /could have English class now.
Why are the students so happy?
a test today
They can’t have a test today.
must/may/might/could/can’t
• Congratulations on passing your exam. You … be very pleased.
• … must …• That woman is asking a lot of questions. She …
be a journalist. Or perhaps she’s a spy.• … may / might / could …
must/may/might/could/can’t
• Relax and do the test. You’re an excellent student. You … fail.
• … can’t …• Where’s Bob? I don’t know. He ... be having lunch.• … may / might / could …• She’s very bad-tempered. She ...have many
friends.• … can’t …
must/might/could/can’t
• A: Do you know where my address book is? B: It ...be in the hall cupboard. I think I saw it
the other day.… may / might / could …• This parcel is making a ticking noise – throw it
out of the window! It ... be a bomb! (September 12th, 2001, in the USA)
• … must …
Speculating about the past
Why are 9th grade students so happy?
They must have done an excellent English test.
They may /might / could have had an English class.
They can’t have done lots of ECA on the weekend.
Speculating about the past
must / may / might / could / can’t+ HAVE
+ PAST PARTICIPLE
Speculate about the past using these verbs:ENJOY LEAVE GO BE SEND
• Henry’s office is locked. He ... home.• ... must have gone ...• I’m not sure but this house ... a school once.• ... might have been ...• Jane is such a nice girl. She ... me this rude e-
mail.• ... can’t have sent ...
Speculate about the past using these verbs:ENJOY LEAVE GO BE SEND
• A: Do you know where my umbrella is? B: No, but you ... it at school. ... may have left ...• I don’t know why you wanted to stay at that
party. You ... talking to all those boring people.• ... can’t have enjoyed ...
Speculate about the past using a SUITABLE verb.
• A: Did you hear the explosion? B: What explosion? A: There was a loud explosion a few minutes
ago. You ... it.... must have heard ...• A: Where is Julia? B: I don’t know. She ... to the toilet.... may have gone ...
Speculate about the past using a SUITABLE verb.
• A: Who was the man we saw with Ann yesterday?
B: I’m not sure. It ... her brother.... might have been ...• You got here very quickly! You ... a taxi.... must have taken ...• It rained every day during their holiday at the
seaside, so they ... a very nice time.... can’t have had ...
Speculate about the past using a SUITABLE verb.
• I wonder why Bob didn’t phone me. He ...... might have forgotten ...• I left my bike outside the house last night and
this morning it isn’t there anymore. Somebody ... it.
... must have stolen ...• I saw some students at the mall, but they
didn’t talk to me. They ... me.... can’t have seen ...