Summary of Modal Verbs of Probability

## Introduction This material covers the use of **modal verbs** to express probability in the present, future, and past, and the basic structure of **nouns** and noun phrases. The content is tailored for high school students: concise explanations, examples, and practical tips. ### What You'll Learn - How to assess the probability of an event using modal verbs (must, can’t, may, might, could) - How to make deductions about the past using perfect infinitives (have + past participle) and continuous perfectives (have + been + -ing) - The basic components of a noun phrase and examples > **Definition:** A modal verb expresses possibility, probability, obligation, ability, or permission. ## 1. Expressing Probability in the Present and Future ### Key Modal Verbs - **must** – logical conclusion, high probability - **can’t** – logical conclusion, very low probability (practically impossible) - **may / might / could** – possibility or lower probability > **Definition:** Using modal verbs to express probability means you are not stating a certainty, but rather drawing a conclusion based on evidence or context. ### Examples - He **must** be exhausted. (Drawing a conclusion based on evidence.) - She **can’t** have a ten-year-old daughter! (It's practically impossible based on known information.) - He **might** be lost. / He **may** be stuck in traffic. - They **could** be at the concert. ### Usage in Context - Short advice: "Take your umbrella. It **might** rain later." – the modal verb suggests a possible future. - Negative forms: **may/might + not**, rarely **couldn’t** in this sense. | Modal Verb | Probability Meaning | Example | |---|---:|---| | must | very probable (logical conclusion) | He must be tired. | | can’t | very improbable (ruled out) | She can’t be here already. | | may / might / could | possibility, uncertainty | They may come later. | Fun fact: Many speakers in everyday conversation interchange may and might because the difference in the intensity of probability is often very slight. ## 2. Questions about Probability - Direct questions with modal verbs (Might she be...?) are uncommon. - A more common way: **Do you think ...?** + a sentence with a modal or a conclusion. Examples: - „Do you think she's married?" – "She can't be." - "Where do you think he's from?" – "He might be Portuguese." - If you use a modal verb in the question, it often comes after "Do you think": - "Do you think he might be Portuguese?" > **Definition:** A question starting with "Do you think..." allows for a polite expression of conjecture or a question about an opinion. ## 3. Deductions about the Past ### Perfect Infinitive (have + past participle) - Used to express a deduction about something that happened in the past. - Examples: - He **must have caught** a later train. (A strong deduction about a past event.) - They **might have lost** our phone number. - She **can't have told** him about us yet. - The letter **may have got** lost in the post. ### Perfect Continuous Infinitive (have + been + -ing) - Used to make a deduction about an ongoing activity in the past. - Examples: - She **must have been joking**. (A strong deduction about an ongoing past action.) - They **can't have been trying** very hard. | Form | Usage | Example | |---|---:|---| | have + past participle | Deduction about a completed past event | He might have changed his mind. | | have + been + -ing | Deduction about an ongoing past activity | She must have been working late. | Did you know that perfect infinitives are often used in journalism and storytelling when the speaker interprets evidence about past events? ## 4. Noun phrases - A noun phrase contains a noun and may include prepositions, adjectives, or pronouns. Examples of simple noun phrases: - book - a book - my book > **Definition:** A noun phrase is a group of words that has a noun as its core and functions in a sentence as a subject, an object, or an adverbial complement. ### Components of