Solving mysteries: making deductions about the past
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Think about these questions before listening. Share your ideas with a partner.
- Think about a time you lost something important. What were your initial theories about what might have happened to it?
- What is a famous unsolved mystery from your country or from history that you find fascinating? What do people think must have happened?
- Describe a situation where you had to be a 'detective' in your own life to solve a small problem. What clues helped you make your deductions?
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The Mystery of the Missing Sandwich
Listen to the dialogue. Notice how the vocabulary and grammar from the lesson are used.
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Answer these questions in your own words. Support your answers with evidence from the audio recording.
01What is the central mystery that Marco is trying to solve?
Sample answerHe is trying to figure out why his special tuna sandwich has disappeared from the office fridge.
02Who is the first person Marco eliminates as a suspect, and what is his reason?
Sample answerHe rules out their manager because the manager is working from home and therefore couldn't have taken the sandwich.
03What potential clue does Emma point out, and how does Marco interpret it?
Sample answerEmma mentions the note about cleaning the fridge, but Marco believes it's a 'red herring' and not a real clue.
04What is Marco's main theory about the culprit, and what evidence supports it?
Sample answerHe has a hunch it was an 'inside job' by a colleague who knows his Friday routine. The fact that only his specific sandwich was taken supports this theory.
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Key vocabulary for discussing mysteries
Vocabulary
These expressions will help you discuss deductions and investigations more precisely.
Examples
To piece together the evidence — to gradually understand a situation by collecting and combining different pieces of information.
Usage note: This is often used when talking about investigations. You can also 'piece together the clues' or 'piece together what happened'.
A red herring — a clue or piece of information that is misleading or distracting from the real issue.
Usage note: This is a common idiom in detective stories and discussions about complex problems. For example, 'The first clue turned out to be a red herring'.
To rule out (a possibility/a suspect) — to eliminate something as a possibility or decide that someone is not responsible.
Usage note: This is a key part of the process of deduction. It's often used in the passive voice, e.g., 'The neighbor was quickly ruled out as a suspect'.
An inside job — a crime, especially a theft, committed by someone with internal knowledge, like an employee or resident.
Usage note: Use this when you suspect the culprit had special information that an outsider wouldn't have, such as a security code or the location of valuables.
To have a hunch — to have a feeling or guess based on intuition rather than facts or proof.
Usage note: This is a common and slightly informal phrase. It's often followed by a 'that' clause, e.g., 'The detective had a hunch that the witness wasn't telling the whole truth'.
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Connecting the clues
Can you solve the case? Match the beginning of each sentence to its logical ending.
Match each item on the left with the correct item on the right.
Drag or click to match
Definitions
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Grammar: Modals of deduction for past events
Grammar
We use modal verbs like 'must have', 'can't have', and 'might have' followed by a past participle to make logical guesses about past events. When investigating a mystery or discussing a past situation, these verbs help us express how certain we are about our conclusions based on the available evidence.
Examples
The lights in the house are off and the car is gone. They must have left for their holiday already.
Use 'must have + past participle' when you are almost certain something happened based on strong evidence.
He was seen in London at noon. He can't have committed the crime in Paris at one o'clock.
Use 'can't have' or 'couldn't have + past participle' to express that you believe something was impossible.
The detective found a footprint in the garden. The culprit might have escaped through the back window.
Use 'might have', 'could have', or 'may have + past participle' to suggest a possibility when you are not sure.
Key points
- Structure: modal (must/can't/might) + have + past participle.
- These modals express degrees of certainty about the past, not obligation or ability.
- Common mistake: avoid using 'mustn't have' for deduction. The correct negative form is 'can't have' or 'couldn't have'.
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Find the mistake
Read the sentences below. Each one has a single error related to grammar or vocabulary. Can you spot it and correct it?
Each sentence contains one error. Find and correct it.
01The thief knew the security code, so it must had been an inside job.
Corrected version
The thief knew the security code, so it must had have been an inside job.
02She can't have knew about the secret meeting; she was out of the country all week.
Corrected version
She can't have knew known about the secret meeting; she was out of the country all week.
03The investigation was difficult because there was very little evident to work with.
Corrected version
The investigation was difficult because there was very little evident evidence to work with.
04After finding a solid alibi, the investigators were able to rule him away as a suspect.
Corrected version
After finding a solid alibi, the investigators were able to rule him away out as a suspect.
05I'm not sure, but I do a hunch that the real culprit is someone we haven't considered yet.
Corrected version
I'm not sure, but I do have a hunch that the real culprit is someone we haven't considered yet.
06The detective's initial theory turned out to be a complete red herring, which was very mislead.
Corrected version
The detective's initial theory turned out to be a complete red herring, which was very mislead. misleading.
07The police are still trying to piece together what happened on the crime scene.
Corrected version
The police are still trying to piece together what happened on at the crime scene.
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Complete the sentences with words from the box. One word is extra.
Word bank
01I can't prove it, but I have a strong that the butler is lying about where he was last night.
02The detective was able to the main suspect after his alibi was confirmed by three different witnesses.
03Since there were no signs of forced entry, the police believe the robbery must have been an .
04The mysterious phone call turned out to be a complete , designed to distract the investigators from the real clues.
05It took the investigators months to what really happened on the night of the disappearance.
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The Gardner Museum heist
Read about one of the most famous unsolved art thefts in history.
Read the passage below, then answer the comprehension questions.
In March 1990, two men dressed as police officers convinced security guards to let them into Boston's Isabella Stewart Gardner Museum. Within an hour, they had stolen 13 pieces of valuable art, cutting masterpieces from their frames. The thieves must have had excellent knowledge of the museum's layout, leading many to believe it was an inside job. For decades, detectives have tried to piece together the evidence, but with no witnesses and little forensic data, the case went cold. Every few years a new lead appears, but it often turns out to be a red herring, distracting investigators from the truth. While authorities have managed to rule out several high-profile suspects over the years, the identity of the culprits remains unknown. Many investigators still have a hunch that the artwork was never sold and remains hidden, waiting to be discovered.
01Why do many investigators suspect the theft was an 'inside job'?
Sample answerBecause the thieves seemed to have detailed knowledge of the museum's layout.
02According to the text, what is a major challenge the investigators have faced?
Sample answerThey have had very little evidence to work with, such as a lack of witnesses and forensic data.
03What does the passage mean when it says a new lead often turns out to be a 'red herring'?
Sample answerIt means the new information is misleading and distracts the investigators from the real facts of the case.
04What can you infer about the current status of the stolen artwork?
Sample answerIt is likely still missing, as investigators have a hunch that it is hidden somewhere and has not been sold.
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Discuss these questions with a partner. Try to use vocabulary from the lesson.
- When investigating a real-life mystery, how much should people rely on a 'hunch' versus concrete evidence? Discuss whether intuition is a valuable tool or a dangerous 'red herring' that can mislead investigators.
- Think about popular detective stories or TV shows from your country. Do the detectives usually solve cases by carefully piecing together the evidence, or do they rely on luck and coincidence? What might this suggest about your culture's view on justice?
- Imagine a company's secret project files are stolen from a secure server, and only a few senior managers had the password. Would you immediately suspect it must have been an 'inside job'? What other possibilities would you need to 'rule out' before making a conclusion?