Unit 6: Grammar section. Modal verbs Unit 6: Grammar section.
Three basic rules Except Invariable verbs: -s No auxiliaries: do / does Always followed by INFINITIVE Be able to + INF Have to + INF Need to + INF Except
Ability Present: Can / can’t + INF Ex: Jim can draw very well. Future: Will / won’t + be able to + INF Ex: When I finish my project I will be able to go out with my friends.
Ability Past: [Particular past ability: “poder”] Was / wasn’t or were / weren’t able to + INF [Particular past ability: “poder”] Ex: The boat sank near the beach, so we were able to swim to the shore. Could / couldn’t + INF [General past ability: “saber”] Ex: We could swim when we were 5.
Obligation Necessity / Obligation: Must + INF [Strong / personal] Ex: You must wear a helmet when you ride a bike. Have to + INF [Task] Ex: I have to do my homework before dinner. Need to + INF [Necessity] Ex: I need to go to the bank.
Obligation Lack of Obligation: Don’t / doesn’t have to + INF Ex: You don’t have to sweep the floor, there is someone to do it for you. Needn’t + INF Ex: You needn’t bring anything to the dinner.
BUT Be careful! Need is followed by to + INF in affirmative forms: Ex. I need to go to the bank. The negative form, Needn’t , is only followed by the INF: Ex. You needn’t use your car. BUT
Obligation Prohibition: Mustn’t + INF Ex: Students mustn’t run in the corridors. Can’t + INF Ex: You can’t use the computer after midnight.
advice Affirmative: Should / Ought to + INF Ex: You should / ought to stop eating chocolate if you want to lose weight. Negative: Shouldn’t + INF Ex: You shouldn’t eat so much chocolate if you want to lose weight.
Certainty Sure: Must + INF [I am sure that…] Ex: She must be happy because she has won the car. Impossible: [It’s impossible that…] Can’t + INF Ex: She can’t be at class because she is abroad.
Certainty Possible: May + INF [Stronger] Ex: It may be quicker to travel by train. Might + INF Ex: We might get lost if we don’t use a map.
Certainty Possibility can also be expressed using: Can + INF Ex: We can paint the walls later. Be able to + INF Ex: I think they will be able to win this time. Could + INF [Remote possibility] Ex: We could go on Friday evening.
request Formal: May + INF [Very formal] Could + INF Would + INF Ex: May I use your phone, please? Could + INF Ex: Could you tell me the way to the station? Would + INF Ex: Would you like to help me with the luggage? Informal: Can + INF Ex: Can you speak more clearly?
Suggestion & offer Suggestion: Could + INF [Formal] Ex: You could join our team next week. Can + INF [Informal] Ex: You can sing that song again! Offer: Would+ INF Ex: Would you like a cup of tea?
PERFECT Modal verbs Actions in the past. Modal + have + participle
Certainty Sure: Must + HAVE + PARTICIPLE [A certainty or logical conclusion about an event in the past] Ex: The lights are out. Everyone must have left . Impossible: Couldn’t + HAVE + PARTICIPLE [A certainty that something did not happen] Ex: She couldn’t have done a better job.
Certainty Possible: May / Might + HAVE + PARTICIPLE [A guess about something that happened in the past. You’re not sure of it] Ex: She may / might have read this book, but I’m not sure.
Ability Only in affirmative: Could + HAVE + PARTICIPLE [The ability to do something in the past, but which in the end was not done] Ex: You could have avoided that accident.
Criticism or regret In affirmative: Should / Ought to + HAVE + PARTICIPLE [Advice which was not followed in the past] Ex: You should /ought to have listened to me. [Expectations which were not fulfilled] Ex: They should / ought to have nominated the film for an Oscar. In negative: Shouldn’t + HAVE + PARTICIPLE [Criticism that is given after an event] Ex: He shouldn’t have refused the opportunity.
Desire Would + HAVE + PARTICIPLE [Desire to do something in the past which in fact could not be done] Ex: I would have lend you my car but my father needed it too.
Unnecessary action Needn’t + HAVE + PARTICIPLE [Something that was done but it was not necessary] Ex: You needn’t have raised your voice.