Summary of Advanced English Grammar Guide

## Introduction Modal verbs and conditionals are essential tools for expressing ability, permission, obligation, probability and hypothetical situations in English. This guide breaks down core modals and basic conditional patterns, with clear explanations, examples and comparisons to help you study efficiently. > Definition: A modal verb is a special auxiliary verb used with a bare infinitive to express modality: ability, permission, obligation, probability, or hypothetical attitude. ## Overview: Two modal perspectives - **Primary modality (disposition/attitude):** commands, permission, ability, willingness (e.g. must, have to, can, will, shall) - **Secondary modality (epistemic / certainty):** judgments about truth or likelihood (e.g. must, might, may, can’t) ## Main modals and uses ### Must / Have to / Need to > Definition: Use these to express obligation or necessity; must expresses a strong, often speaker-based obligation; have to expresses external/official obligation; need(n’t) expresses necessity or lack of necessity. - **Must (British primary):** strict, personal obligation. Example: You must go to school. (British; American tends to use need to for normal obligations.) - **Have to (suppletive past forms):** external/official obligation. Example: You have to submit the form by Friday. Past: I had to get up early. - **Need / Needn’t:** - Affirmative: I need to go. (necessity) - Negative British: I needn’t go = it is not necessary (he didn’t have to). American: You don’t need to go. - Examples comparing forms: | Situation | British | American | Meaning | |---|---:|---:|---| | Official rule | He hasn’t got to go to school | He doesn’t have to go to school | not required by rule | | Not necessary (after action) | He needn’t have bought such expensive gifts | He didn’t have to buy such expensive gifts | He did buy them; it was unnecessary | Fun fact: Native speakers often choose between must and have to based on whether the obligation feels internal (must) or external (have to). ### Can / Could > Definition: Can expresses ability, informal permission, or theoretical possibility; could is its past/conditional form. - **Ability:** He can swim in that river. - **Possibility:** In summer it can snow in the mountains. - **Permission (informal):** Can I park here? (less polite than may) - **Could:** past ability or polite requests and conditional possibility: Could you help me?; I could go if I had time. - **Can’t (epistemic):** The horse can’t have won the race (certainty that it did not). - **Can’t help + gerund:** He can’t help laughing at her — used for involuntary emotional reactions. ### May / Might > Definition: May and might express tentative possibility (epistemic) or permission (may as formal permission). - **Possibility:** He may come / He might come. - **Perfect forms:** He may have come = maybe he came. - **Permission (formal):** May I use your computer? — Yes, you may (formal). Compare: You may not do that (you are not allowed). ### Will / Would > Definition: Will indicates future, willingness or strong expectation; would is used for conditional mood, polite requests, habits in the past. - **Will for requests:** Will you help me, please? (polite imperative) - **Repeated present habits:** He will watch TV every evening = he tends to do it. - **Would:** conditional action (If I had time, I would travel), polite requests (Would you excuse me?), past habits (When he was young, he would jog every day). ### Shall / Should / Had better > Definitions: - **Shall:** formal/official prescriptions in legal or formal documents (The participants shall enter through the main entrance). - **Should:** recommendation or expectation. Example: You should come. Past critique: You should have gone. - **Had better:** stronger, warning-like recommendation to avoid bad consequences. Example: You had better visit the party. ### To be / Used / Able / Allowed - **Be (to) / be supposed to:** expresses arranged or reported obli