Grammar Season

Modal verbs Episode

„If I can somehow go back to the beginning of all of this, I might be able to save her.”

– Butterfly Effect


Evan and his friends suffered many severe psychological traumas in their childhood that frequently caused Evan to black out.
As a young adult, Evan discovers that when he reads from his adolescent journals, he can travel back in time and redo parts of his past. However, there are consequences to his revised choices that dramatically alter his present life. Evan keeps this secret to himself because he fears that no one would believe him.
His efforts are driven by the desire to undo the most unpleasant events of his childhood, including saving his childhood sweetheart Kayleigh from being molested by her father and tormented by her sadistic brother, Tommy. She couldn’t stand either of them when she was young.
Evan thinks there must be a way to make things right, so he assures her that whatever happened it wasn’t her fault, she had to do it and she couldn’t have stopped it. He also promises that he will come back for her.
Later, he finds out that his father has the same ability, so he asks him how he can fix the past.
His father was praying this curse would have ended with him, but unfortunately, it didn’t. He tells Evan he cannot make things better and he can’t play God.  He also tells Evan that just by being there, he may be killing his mother.
He ultimately reaches the conclusion that he and his friends might not have good futures as long as he keeps altering the past, and he realizes that he is hurting them rather than helping, so he travels back one final time to do something he should have done earlier…





Types of Auxiliary Verbs

The primary auxiliary verbs are be, do, and have, and they are the most commonly occurring auxiliaries in English. Each can also be used as a main verb in a clause, and each is able to conjugate to reflect plurality, tense, or aspect.

Modal auxiliary verbs (often just called modal verbs) are used to express modality—that is, possibility, likelihood, ability, permission, obligation, or future intention. These are can, could, will, would, shall, should, must, may, and might. They are distinguished by the fact that they are unable to conjugate into different forms, and they are only followed by a verb in its base form.

Modal verbs are defined by their inability to conjugate for tense and they do not take an “-s” at the end when he, she, or it is the subject), and they cannot form infinitives, past participles, or present participles.

Modal auxiliary verbs can also be used to create questions with specific meanings

  • Can you protect me? (question of ability)
  • May I help you? (permission)

Ought to, used to, need, and dare—are known as semi-modal verbs, since they do not share all the characteristics of the modal verbs above and only function as auxiliary verbs in certain ways.






As a modal auxiliary verb, ‘will’ is particularly versatile, having several different functions and meanings. It is used to:

Form future tenses:

  • “I will come back for you.”


Express willingness or ability:

  • “This washing machine won’t turn ”


Make requests or offers:

  • “Will your friend join us for dinner?”


Complete first conditional sentences:

  • “If it rains, we will take a taxi.”


Express likelihood in the immediate present:

  • “That will be Evan – I’m expecting him”


We use will and won’t when we are very sure:

  • “She’ll be at work now.”


Issue commands:

  • “This house will not be used as a hotel for your friends, do you understand me?”





The modal auxiliary verb ‘shall’ is used in many of the same ways as ‘will’: to form future tenses, to make requests or offers, to complete conditional sentences, or to issue maxims or commands. Although ‘will’ is generally preferred in modern English, using ‘shall’ adds an additional degree of politeness or formality to the sentence that will sometimes lacks.

Generally, ‘shall’ is only used when I or we is the subject, though this is not a strict rule and does not apply at all when issuing commands.

  • “Shall I open the window?”
  • “Shall we go to the cinema?”





It is used in place of will for things that happened or began in the past:

  • “His mother wouldn’t let him go to the party.”


Like ‘shall’, it is sometimes used in place of will to create more formal or polite sentences:

  • “Would someone just tell me already what the hell happened in the mailbox?”
  • “Guys, slow up, would you?”


It is also used to express requests and preferences:

  • “Would you please help me?”
  • “Would you rather go biking or go for a hike?”


Describe hypothetical situations:

  • “She would join your study group, but she doesn’t have any free time after school.”
  • “You wouldn’t believe me.”
  • “Why would that freak me out?”
  • “Please, Evan. Don’t even joke. He wouldn’t hurt you.”


Politely offer or ask for advice or an opinion:

  • “What would you suggest we do instead?”
  • “I would talk to her tonight…”


The past of ‘will’ in reported speech:

  • When we use ‘will’ in direct speech, we often use ‘would’ to change it into reported speech.

Direct speech: “I will be there at 6pm.”
Reported speech: She said that she would be there at 6pm.


Habits in the past:

  • “When we were children, we would go to the beach every summer.”
    (This is similar in meaning to ‘used to + infinitive’; you can learn it in ‘Everything used to be relative’ episode.)

The second conditional:

  • “If I had enough money, I would travel around the world.”
  • “If we lived in Madrid, we would study Spanish.”

The third conditional:

  • “If I had gone to bed earlier, I wouldn’t have been so tired.”
  • “If the train hadn’t been late, we would have arrived on time.”

With ‘wish’:

  • “I wish that he wouldn’t smoke so much.”
  • “I wish you would come to see me more often.”




The modal verb ‘should’ is used to:

Politely express obligations or duties:

  • “I think she should pay for half the meal.”
  • “She should not be here; it’s for employees only.”


Ask for or issue advice, suggestions, and recommendations:

  • “Should I call the doctor?
  • “Someone should check the mailbox.”
  • “We should go soon. If Dad catches us smoking down here, we’re dead.”
  • “Uh, we should be getting to class now.”


Describe an expectation:

  • “She should be here by now.”


Create conditional sentences:

  • “If anyone should ask, I will be at the bar.”




As a modal auxiliary verb, ‘can’ is most often used to:

Express a person or thing’s ability to do something:

  • “Mom. Don’t cry. I can change this.”
  • “Evan can’t take his eyes off her.”


Express or ask for permission to do something:

  • “I’m sorry, but can it wait ‘til tonight? I’m already late for work.”
  • “Can I have the picture?”


Describe the possibility that something can happen:

  • “People forget that you can get skin cancer from tanning beds.”
  • “Kayleigh… no! You can’t die again!”


Issue requests and offers:

  • “Can you give me some legal advice?”
  • “But there’s something else you can try to monitor his memory.”


 Write CANNOT.
 Both ‘cannot’ and ‘can not’ are acceptable spellings, but the first is much more usual. You would use ‘can not’ when the ‘not’ forms part of another construction such as ‘not only’.


Be able to


We use ‘be able to’ to talk about special ability. Be able to is possible in all tenses – but ‘can’ is possible only in the present and ‘could’ is possible only in the past for ability. In addition, ‘can’ and ‘could’ have no infinitive form. So we use ‘be able to’ when we want to use other tenses or the infinitive.


  • Evan won’t be able to make things right in a week!
  • When I blacked out yesterday, I was able to travel time.
  • “Evan, did I tell you? My mother said I might be able to visit her this summer in Orlando with her new family.”
  • “All I know is that I might be able to unblock some of my repressed memories.”




The modal verb ‘could’ is most often used as a past-tense version of ‘can’.

Indicating what someone or something was able to do in the past:

  • “When I was younger, I could run for 10 miles without breaking a sweat!”
  • “I couldn’t cut the rope.”
  • “I couldn’t tell if they were real memories or just phantoms.”


It can also be used instead of can as a more polite way of making a request or asking for permission:

  • “Could you help me remember what happened?”
  • “Could you please be quiet?”


To express a slight or uncertain possibility:

  • “She could be in big trouble over this.”
  • “It could be extremely useful to jog his memory.”


To make a suggestion or offer:

  • “We could go out for a drink after work on Friday.”





The modal verb ‘may’ is used to:

Request, grant, or describe permission:

  • “May I borrow your diary?”


Politely offer to do something for someone:

  • “May I help you?”


Express the possibility of something happening or occurring:

  • “I’m worried that my nose may start bleeding soon.”
  • „Now your father may seem sleepy to you, but that’s just because of his medicine, okay?”
  • „Look, Kayleigh. This may sound like bullshit coming from a guy who hasn’t spoken to you in seven years…”


Express a wish or desire that something will be the case in the future:

  • “May the force be with you.”


Express or introduce an opinion or sentiment about something:

  • “May I just say, this has been the most wonderful experience of my life.”





The modal verb ‘might’ is most often used to:

Express an unlikely or uncertain possibility:

  • “Thought you might like some fresh air for a change.”
  • “All I know is that I might be able to unblock some of my repressed memories.”
  • “It might be a little scary.”


Ask for permission in a very formal and polite way:

  • “Might I ask you a few questions?”


Suggest an action:

  • “You might ask your brother about repaying that loan the next time you see him.”


Ask permission in reported speech (as the past-tense form of may):

  • “He asked if he might use the car for his date tonight.”




The modal verb must is most often used to:

Express necessity (Something has to happen or be the case):

  • “This door must be left shut at all times!”
  • “You mustn’t (must not) tell anyone about what we saw.”


Be careful about the difference between ‘mustn't’ and ‘don't/doesn’t have to’! 
‘Mustn't’ means it's not allowed, or it's a bad idea:
“You mustn’t speak when the teacher is speaking.”

Don't have to’ means you don't need to do something, but it's fine if you want to do it:
“You don’t have to wear a tie in our office. You can wear a tie if you want to but it’s OK if you don’t.”


Indicate a strong intention to do something in the future:

  • “I must fix the car this weekend.”


Emphasize something positive that you believe someone should do:

  • “You must come stay with us at the lake sometime.”
  • “It must end with me.”


Rhetorically introduce or emphasize an opinion or sentiment:

  • “I must say, this has been a most wonderful evening.”


Indicate that something is certain or very likely to happen or be true:

  • “You must be absolutely exhausted after your black out.”
  • “He must be at least a foot taller than me.”
  • “There must be a way to fix this.”
In this case the opposite of ’must’ is cannot or can’t! 



+ Have to/ has to


Have to and must are both used to express obligation. There is a slight difference between the way they are used.

‘Have to’ shows us that the obligation comes from somebody else. It’s a law or a rule and the speaker can’t change it:

  • “I have to work today.”
  • “Do you have to wear uniform?”
  • “You have to promise that this will be our little secret. Think you can do that?”


Present: have/has to - don’t/doesn’t have to
Past: had to - didn’t have to


Must shows us that the obligation comes from the speaker. It isn’t a law or a rule:

  • “I must call my mother tonight.”
  • “I must study today.”



Must also changes to ‘had to’ in the past. ‘Had to’ is not equal to ‘must have been’!

Remember: 'must have done' is a modal verb of deduction or speculation, not obligation in the past!



+ Ought to


‘Ought to’ is a semi-modal verb because it is in some ways like a modal verb and in some ways like a main verb. For example, unlike modal verbs, it is followed by to, but like modal verbs, it does not change form for person. ‘Ought to’ and ‘should’ are similar in meaning. ‘Should’ is more common than ‘ought to’. ‘Ought to’ is more formal than ‘should’.

We use ought to when talking about things which are desired or ideal:

  • “They ought to have more parks in the city centre.”


We can use ought to when we talk about what is likely or probable:

  • “There ought to be some good films at the cinema this weekend.”

(We can also use ‘ought to + have + past participle’ form to talk about things that were desired or ideal in the past but which didn’t happen. It can express regret = ‘should + have + past participle’.)





These past modal verbs are all used hypothetically, to talk about things that didn’t really happen in the past.


Deduction (past)


In the same way that we use modal verbs to say how certain we are about things in the present we can also use them to speculate about the past.

When we use modal verbs to talk about the present, they are followed by an infinitive without ‘to’. When we use modal verbs to talk about the past they are followed by ‘have + past participle’ (‘have been’, ‘have gone’ have eaten’ etc.)


Must + have + past participle


We use ‘must + have + past participle’ when we feel sure about something in the past:

  • “Something must’ve happened! What set him off?”
  • “- I emancipated myself when I was fifteen.”
    “- Wow. That must’ve taken some courage. “
  • “Oh no! Where’s my car? Someone must have stolen it!”



Might/may/could + have + past participle


We use might, may or could with ‘have+ past participle’ to say that we think something was possible but we aren’t sure:

  • “I’m not sure. I might have gotten some stories mixed up.”
  • “I couldn’t tell if they were real memories or just phantoms. You know, he might only have thought he actually them…”
  • “I think something really bad might’ve happened to us.”
  • “He should be here by now. He may have been delayed by a traffic jam or something.”
  • “I can’t find my purse. I could have left it in the supermarket but I just don’t know.”
  • “– Where is Evan? Why isn’t he here?
    – He could have missed the bus.”


Can’t + have + past participle


We use ‘can’t + have + past participle’ when we feel sure something didn’t happen in the past:

  • I thought I saw Kayleigh in town this morning but it can’t have been her – she’s in New York this week.



Hypothetical past ability


Could + have + past participle


We use ‘could + have (+ past participle)’ or ‘would have been able to’ to talk about hypothetical events in the past. They can be used in the positive and the negative.

‘Could + have + past participle’ and ‘would have been able to’ mean that something was possible in the past, or you had the ability to do something in the past, but that you didn’t do it:

  • “I could have gone to university but I decided to get a job.”
  • “I would have been able to make things right but I blacked out.”
  • “You were 7 years old and there’s nothing you could’ve done to deserve…”


‘Couldn’t + have + past participle’ means that something wasn’t possible in the past, even if you had wanted to do it:

  • “Whatever happened, it wasn’t our fault. You know we couldn’t have stopped it.”
  • “I couldn’t have done it without your help.”
  • “Couldn’t you have moved in with your mom?”
  • “I wouldn’t have been able to afford it even if it had been for sale.”



Would + have + past participle


In most cases we use it as a part of the third conditional:

  • “If I had had enough money, I would have bought a car.”


Because ‘would’ (and will) can also be used to show if you want to do something or not, we can also use ‘would + have + past participle’ to talk about something you wanted to do but didn’t.
This is very similar to the third conditional, but we don’t need an ‘if clause’:

  • “I would have gone to the party, but I was really busy.”
  • “I would have called you, but I didn’t know your number.”
  • “I was praying this curse would have ended with me.”
  • “Mom never would’ve started smoking in the first place.”



Should + have + past participle


On the one hand ‘should + have + past participle’ can mean something that would have been a good idea, but that you didn’t do it. It’s like giving advice about the past when you say it to someone else, or regretting what you did or didn’t do when you’re talking about yourself:

  • “It’s my fault. I should have told you he was released a few weeks ago.”
  • “It’s freezing. I should have brought my coat.”

On the other hand ‘shouldn’t + have + past participle’ means that something wasn’t a good idea, but you did it anyway:

  • “Well, thanks for seeing me, man. I shouldn’t have waited so long.”
  • “She had a new family. Not enough space for me. Said I should have moved in with her when we were kids. But… whatever.”


We can also use ‘should + have + past participle’ to talk about something that, if everything is normal and okay, we think has already happened. But we’re not certain that everything is fine, so we use ‘should have’ and not the present perfect or past simple. It’s often used with ‘by now’:

  • “Evan should have arrived to Philadelphia by now.”






To black out:
To lose consciousness; To experience a period of time about which one does not remember anything.

(Note: blackout: a period of darkness (as in a city) caused by a failure of electrical power).

A young person who is developing into an adult.

To do over or again.

To make different in some particular, as size, style, course, or the like; modify.

To keep a secret:
(collocation) To know a secret and not tell anyone.

Here in this example (…are driven by…):

(Psychology) An inner urge that stimulates activity.

Causing discomfort, unhappiness

To find out something:
(phrasal verb) To gain knowledge of (something); learn by study, observation, or search.

To reach a conclusion:
(collocation/ idiom) To make a judgment or decision after a period of thought or research. /To complete discussion and decide an issue.  

As long as:
If it is the case that; provided that.