Making deductions: expressing certainty and uncertainty

Summary

This 90-minute ESL lesson for B2 learners explores Making deductions: expressing certainty and uncertainty through a real article. Across 10 interactive exercises, you'll develop reading comprehension, vocabulary, grammar, practical communication, speaking skills — all built around authentic English content.

What you'll practise:

• 5 key vocabulary items with definitions and usage notes
• Grammar focus: Modals of deduction in the present and past with examples and practice
• Real-world phrases for troubleshooting a problem at work
• Gap-fill and cloze exercises to test vocabulary in context
• Error correction to sharpen grammar awareness

Lesson activities (10 exercises)

Each exercise builds on the previous one. Work through them in order for the best learning experience.

1. Warm-up — Discussion questions to activate what you already know about the topic.
2. Comprehension — Answer questions to check your understanding of the main ideas and supporting details.
3. Grammar — Study Modals of deduction in the present and past — explanation, examples, and key rules.
4. Error correction — Find and fix the mistake in each sentence — a great grammar workout.
5. Vocabulary — Learn key words and expressions from the article, with definitions and usage notes.
6. Fill the gaps — Complete sentences with the correct vocabulary. Drag and drop or type your answers.
7. Practical English — Learn phrases for troubleshooting a problem at work — ready to use in real conversations.
8. Multiple choice — Choose the correct answer from four options — testing comprehension and language use.
9. Discussion — Reflect on the topic and share your opinions using the language you've learned.

Vocabulary

This lesson introduces 5 key terms drawn directly from the article:

• A gut feeling — an intuition or instinct you have about a situation, not based on facts or evidence.
• To jump to conclusions — to make a decision or form an opinion about something too quickly, without knowing all the facts.
• On the balance of evidence — a phrase used to say that something is the most likely conclusion after considering all the available information.
• To read between the lines — to understand someone's real feelings or intentions from what they say or write, even if it is not explicitly stated.
• A safe bet — something that is very likely to be true, to happen, or to be successful.

Grammar

This lesson focuses on Modals of deduction in the present and past.

Modals of deduction (must, can't, might, may, could) express how certain we are about something based on evidence. We use them with a base verb to speculate about the present, and with 'have + past participle' to make deductions about the past. This is essential for logically inferring information that isn't explicitly stated.

Examples from the lesson:

• Her phone is going straight to voicemail. She must be on the plane already. — Use 'must + infinitive' when you are almost 100% certain that something is true in the present based on strong evidence.
• The report isn't in my inbox. He might have forgotten to send it, or perhaps the email is just delayed. — Use 'might/may/could + have + past participle' to express a possibility in the past. These modals show you are uncertain.
• She can't have finished the entire project by herself in one day; it was far too complex. — Use 'can't have + past participle' for strong certainty that something was impossible or did not happen in the past. We do not use 'mustn't have' for this.

Key rules:

• Use 'must' for strong positive certainty and 'can't' for strong negative certainty.
• For past deductions, the structure is 'modal + have + past participle'.
• Common mistake: Don't use 'mustn't' for deduction. 'Mustn't' expresses prohibition, while 'can't' expresses impossibility.

Practical English

troubleshooting a problem at work

When something goes wrong at work, you often need to discuss possible causes with your team before you have all the facts. These phrases will help you speculate effectively, showing how certain or uncertain you are about your ideas.

Phrases you'll learn:

• "My money's on the new software update." — This is an informal way to say you are almost certain about the cause of a problem.
• "I wouldn't be surprised if the server is overloaded." — Use this to suggest a very possible cause that seems logical to you.
• "I'm not so sure about that. It could just be a connection issue on our end." — A polite way to express doubt about someone's deduction and suggest a simpler alternative.
• "What's your take on this?" — This is a direct way to ask for someone's opinion or deduction about the situation.
• "We can probably rule out a hardware failure." — Use this when you are fairly certain something is *not* the cause, often based on some evidence.