Modal verbs of speculation and deduction
Say how sure you are with must, might, may, could and can't, about the present and the past.
Explanation
Modal verbs of speculation and deduction are used to express degrees of certainty or uncertainty about a past, present, or future situation. They indicate the speaker's belief, opinion, or judgment regarding the likelihood of something happening or being true. Some common modal verbs used for speculation and deduction include "must," "might," "may," "could," "can't," and "should." Here's a detailed explanation of each:
Must
Usage: It indicates a high degree of certainty or strong belief that something is true or likely to happen.
Example:
- "She must be at home by now." (High probability that she is at home.)
Might/May
Usage: It indicates a possibility or likelihood of something happening, but with less certainty than "must."
Example:
- "He might/may have forgotten about the meeting." (There is a possibility that he forgot.)
Could
Usage: It suggests a possibility, often used when considering several options or when there is uncertainty.
Example:
- "It could rain later, so bring an umbrella." (There is a possibility of rain.)
Can't
Usage: It indicates a strong belief that something is not true or unlikely to happen.
Example:
- "She can't have finished all her homework already." (It's unlikely that she finished.)
Should
Usage: It suggests a strong likelihood or expectation that something is true based on logical reasoning or previous experience.
Example:
- "He should be here by now." (Based on the expected time frame, he is expected to be here.)
Speculation in the Past
To speculate about past events, modal verbs are followed by a perfect infinitive (e.g., "must have," "might have," "could have").
Example:
- "She must have missed the train." (She missed the train, that's why she's late.)
Deduction in the Present and Future
Modal verbs of speculation and deduction can be used to make deductions about present or future situations based on evidence or logical reasoning.
Example:
- "He can't be at work because his car is still in the driveway." (It's unlikely that he's at work because his car is here.)
Practice
Exercise 1
Choose the correct answer.
1. She ______ be at home, but I'm not sure.
2. The lights are off, so they ______ gone out.
3. He ______ be the thief; he was with me the whole time.
4. He speaks so many languages; he ______ very intelligent.
5. They didn't answer the phone; they ______ seen the caller ID.
6. She ______ come to the party, but she's not sure yet.
7. You ______ mistaken him for his twin brother; they look exactly alike.
8. This ______ be the right address! There's no building here.
9. He ______ forgotten about our meeting. He's usually on time.
10. You ______ be joking! That can't be true.
Exercise 2