Cultural clues and certainty

Choose must, might, or can’t. Give one reason from the clue. 🕵️

1. The cinema lights are off, the doors are locked, and no staff are inside. The cinema ___ be open.
2. Ana has a ticket for tonight’s jazz concert, but we do not know if she will go. She ___ be at the concert.
3. Leo knows every song by that band and is wearing their tour T-shirt. He ___ be a fan.
4. The book is in Japanese, and Mia cannot read Japanese. She ___ understand every page.
5. The gallery is crowded and people are taking photos of one painting. It ___ be famous.
6. The actor is on stage in London now. He ___ be filming in Rome at this moment.
7. The film has won several awards, but you have not seen it. It ___ be excellent.
8. The museum closes at 6:00; it is 8:00 p.m. The visitors ___ be inside now.

Building deduction sentences

For past actions, use must / might / may / could / can’t + have + past participle.

The audience is leaving now. The film must be over.
The audience left early yesterday. The film must have been disappointing.

Follow the evidence chain

Put the present-time reasoning in a logical order.

Now follow a past-time clue.

Choose the complete deduction

Use the clue to select a complete sentence.

The venue is empty at 11 p.m.; the show is over. The show [___] .

The review was published yesterday, so the critic saw the film before then. The critic [___] .

We have no information about the composer’s plans. She [___] .

Complete the deduction

This painting has the artist’s name and date on it. It [___] authentic.

The seats were all wet after the storm. The concert [___] outside.

Kim was on a live TV interview at 9:00. She [___] at the theatre then.

The final scene is unclear. The hero [___] alive after the accident.

The missing museum statue

Read the mystery aloud. Decide what each clue proves. 🔎

The City Museum’s small gold statue disappeared during the opening night of a film exhibition. At 8:45, the display case was locked and the valuable statue was inside. At 9:00, the lights went out for two minutes. When they came back on, the case was open and the statue was gone.

Three people were near the room. Nina, the curator, says she was speaking to guests in the cinema hall. Several guests saw her there, so she has an alibi. Omar, a film critic, was outside on the phone; a security camera shows him leaving the building at 8:55. Rosa, an actor, arrived at 9:03 and found muddy footprints near the case. She also found a gold glove. The guard says only staff had keys, but the lock has no damage. Rosa wore silver gloves in photos from that evening. Nina’s key is missing. Who took the statue?

Difficult words

• display case — a glass box used to show valuable objects
• valuable — worth a lot of money
• curator — a person who manages a museum collection
• alibi — proof that someone was somewhere else
• security camera — a camera that records what happens in a place
• footprints — marks left on the ground by shoes
• lock — the part of a door or case that needs a key
• statue — an object shaped like a person or animal

1. What happened at 9:00?
2. Why can’t Omar have taken the statue during the power cut?
3. What evidence suggests that the thief had a key?
4. Who is the strongest suspect, and what evidence supports this conclusion?

Evidence in two photos

Describe what you can see.

• What must have happened?
• What might have happened before the photo?
• Make one sentence with can’t have been.

Describe what you can see.

• What might be going on?
• Connect this photo to the first photo.
• Make one deduction with must, one with might, and one with can’t.

Film festival detective interview

Situation: A rare screenplay has disappeared from a film festival archive.

Your role

Round 1: The teacher is the witness. Ask two questions and make two deductions.

Round 2: You are the witness. Explain the evidence and defend one conclusion.

Useful questions:

• Where were you at 8:00?
• What did you see near the archive?
• Who had access to the screenplay?
• What makes you think that?
• Is it certain or only possible?

Useful language:

• The window is broken, so someone must have broken in.
• It might have been a visitor.
• It can’t have been the manager because they were on stage.
• The person in the black coat could have been the thief.
• The evidence suggests that …

Write a mystery review

Write a 60–120 word mini mystery review of a film, book, or imagined story.

Include:

• the name of the cultural work;
• one piece of evidence;
• one certain present deduction;
• one possible present deduction;
• one certain past deduction;
• one impossible past deduction.

Useful phrases:

• The ending was surprising because …
• The director must be …
• The final scene might be …
• The detective must have known …
• The suspect can’t have been …
• The evidence suggests that …
• This story must be a masterpiece.

Suggested shape:

1. Name the film, book, or story.
2. Describe the mystery or ending.
3. Give evidence-based deductions.
4. Finish with your review.

Check before you finish:

• □ 60–120 words
• □ Cultural work named
• □ Evidence included
• □ Present and past deductions used
• □ must, might/may/could, and can’t used accurately
• □ Clear, coherent review

Today’s detective toolkit

Strong conclusion:

must / must be / must have been

Possible explanation:

might / may / could / might be / might have been

Impossible explanation:

can’t / can’t be / can’t have been

Say one past deduction from today’s museum, concert hall, or film festival mystery without looking at the board. 🎬

For next time

Watch a short film trailer or read a book blurb. Write six evidence-based deductions:

• three about now;
• three about earlier events;
• use must, might / may / could, and can’t.