One Picture, Endless Possibilities: Practicing Deduction in the Classroom

 Modal verbs of deduction can be a tricky topic for students, and at B2–C1 level, they need to show their ability to choose between must, might, could, can’t, or couldn’t have and do it with confidence. One of the most effective ways to help learners master this subtle grammar point is through visual storytelling and speculation.

In this post, I’m sharing  creative ideas for using photo-based cards and ready-to-use conversation questions to bring modal verbs to life. Perfect for speaking practice, grammar review, or an engaging warm-up.

Visuals make abstract grammar tangible. A strange or surprising photo immediately invites curiosity and speculation — and that’s exactly the space where modals of deduction naturally fit.

We ask questions like:

• “What must have happened before this?”

• “Who might have done this?”

• “That can’t be right... can it?”

Students don’t just learn the forms — they use them meaningfully.

I’ve created a series of photo prompt cards — each showing a funny, bizarre, or confusing scene. Alongside each image are targeted questions for both present and past deduction.

Examples include:

• A soaked dog on a couch

• A man in a suit climbing out of a pool

• A laptop covered in peanut butter

• A person barefoot in the snow

Each image sparks a mini-mystery, and students become grammar detectives.

Here are some practical, adaptable ways to use the cards:

1. Guess the Backstory

Skills: Speaking, storytelling
How: Show an image. In pairs, students discuss what might have happened using modals of deduction. Then share their best (or funniest) theory with the class.

2. The Detective Game

Skills: Critical thinking, group discussion
How: Each group gets one card and must prepare a full theory about what happened, using must/might/can’t have.... Then they present their findings like detectives reporting on a case.

3. Write a News Story

Skills: Writing, grammar in context
How: Students write a mini news report based on the image, starting with a headline and using at least three modal structures in the article.

4. Story Puzzle (with multiple images)

Skills: Creative thinking, fluency
How: Give each group 2–3 images. They must create a story connecting all of them, using modal verbs throughout to explain what must/might/can’t have happened.

Want the Cards?

If you're interested in getting these picture prompt cards, just drop me a message! A set contains of:

- 20 cards with pictures and questions 

- 20 cards with pictures

and it can be yours for 20zł.