Modal Deduction & Probability

Lesson focus

Degrees of certainty, deduction, possibility and expectation with modal verbs in present and future contexts

Advanced aim: Express graded certainty and evidential reasoning; the advanced skill is calibrating force rather than memorising modal labels.

Strong positive deduction

Use must for a strong logical conclusion based on available evidence.

  • Example: The lights are on and her car is outside; she must be at home.
  • In another context: Separate scenario: The lights are on and her car is outside; she must be at home.

C1 focus: Choose this form for the intended meaning and discourse effect; nearby alternatives may be grammatical but can change viewpoint, scope, time reference or register.

Strong negative deduction

Use can't for a strong conclusion that something is impossible or highly unlikely.

  • Example: That can't be the final version; several sections are still missing.
  • In another context: Follow-up case: That can't be the final version; several sections are still missing.

C1 focus: Choose this form for the intended meaning and discourse effect; nearby alternatives may be grammatical but can change viewpoint, scope, time reference or register.

Neutral possibility

May, might and could can express specific possibility. Their relative strength is highly context-dependent, so avoid treating them as a fixed probability scale.

  • Example: The delay might be caused by a problem at the distribution centre.
  • In another context: The approval delay might be caused by a problem at the dispatch depot.

C1 focus: Choose this form for the intended meaning and discourse effect; nearby alternatives may be grammatical but can change viewpoint, scope, time reference or register.

Expected outcome

Should can express an expectation based on normal circumstances.

  • Example: The parcel should arrive by lunchtime if traffic is normal.
  • In another context: The sample shipment should arrive by lunchtime if traffic is normal.

C1 focus: Choose this form for the intended meaning and discourse effect; nearby alternatives may be grammatical but can change viewpoint, scope, time reference or register.

Assumptive will

Will can express a confident assumption about a present situation, especially in conversation.

  • Example: That'll be Marcus calling; he said he'd ring around six.
  • In another context: That'll be Daniel calling; he said he'd ring around six.

C1 focus: Choose this form for the intended meaning and discourse effect; nearby alternatives may be grammatical but can change viewpoint, scope, time reference or register.

General possibility with can

Can is common for general or theoretical possibility rather than one specific uncertain event.

  • Example: Even experienced negotiators can misread the mood of a room.
  • In another context: Follow-up case: Even experienced negotiators can misread the mood of a room.

C1 focus: Choose this form for the intended meaning and discourse effect; nearby alternatives may be grammatical but can change viewpoint, scope, time reference or register.

Specific possibility with could

Could can describe a specific possible explanation or outcome.

  • Example: The error could be the result of an outdated data feed.
  • In another context: The reporting inconsistency could be the result of an outdated information feed.

C1 focus: Choose this form for the intended meaning and discourse effect; nearby alternatives may be grammatical but can change viewpoint, scope, time reference or register.

Probability phrase

May well strengthens may and suggests that something is quite possible.

  • Example: The policy may well create more problems than it solves.
  • In another context: The disclosure procedure may well create more problems than it solves.

C1 focus: Choose this form for the intended meaning and discourse effect; nearby alternatives may be grammatical but can change viewpoint, scope, time reference or register.

Remote possibility

Might can signal a more tentative possibility when the speaker wants to avoid sounding certain.

  • Example: There might be another explanation that we haven't considered.
  • In another context: Separate scenario: There might be another explanation that we haven't considered.

C1 focus: Choose this form for the intended meaning and discourse effect; nearby alternatives may be grammatical but can change viewpoint, scope, time reference or register.

Inference from absence

Can't normally expresses negative deduction, not prohibition, when the context is evidential.

  • Example: He can't be in the office; his access card hasn't been used today.
  • In another context: He can't be in the temporary workspace; his access card hasn't been used today.

C1 focus: Choose this form for the intended meaning and discourse effect; nearby alternatives may be grammatical but can change viewpoint, scope, time reference or register.

C1 takeaway

Do not ask only “Which form is grammatically possible?” Ask what the speaker is presenting as background or foreground, completed or ongoing, certain or tentative, generic or specific, neutral or emphatic. Advanced grammar is the control of those choices.

Exercises:

Degrees of certainty, deduction, possibility and expectation with modal verbs in present and future contexts

1
Write the missing grammar chunk so the sentence matches the cue: [Strong positive deduction]
Follow-up case: The lights are on and her car is outside; she _____ at home.
2
Fill the gap with the form that best fits the intended register and meaning: [Strong negative deduction]
Alternative case study: That _____ the final version; several sections are still missing.
3
Complete the gap with the form that best expresses the stated C1 meaning: [Neutral possibility]
The technical hold-up _____ by a problem at the logistics terminal.
4
Supply the missing structure. Choose the form that preserves the intended viewpoint: [Expected outcome]
The replacement part _____ by lunchtime if traffic is normal.
5
Complete the sentence with the most precise form for this context: [Assumptive will]
_____ Ravi calling; he said he'd ring around six.
6
Write the missing grammar chunk so the sentence matches the cue: [General possibility with can]
Alternative case study: Even experienced negotiators _____ the mood of a room.
7
Fill the gap with the form that best fits the intended register and meaning: [Specific possibility with could]
The data-entry fault _____ the result of an outdated material feed.
8
Complete the gap with the form that best expresses the stated C1 meaning: [Probability phrase]
The safeguarding framework _____ more problems than it solves.
9
Supply the missing structure. Choose the form that preserves the intended viewpoint: [Remote possibility]
Follow-up case: There _____ another explanation that we haven't considered.
10
Complete the sentence with the most precise form for this context: [Inference from absence]
He _____ in the satellite branch; his access card hasn't been used today.

Degrees of certainty, deduction, possibility and expectation with modal verbs in present and future contexts

1
Select the option that best expresses the stated relationship: [Strong positive deduction]
Alternative case study: The lights are on and her car is outside; she _____ at home.
2
Which form is the best fit for this context? [Strong negative deduction]
Regional example: That _____ the final version; several sections are still missing.
3
Choose the most precise completion for the sentence: [Neutral possibility]
The processing backlog _____ by a problem at the regional warehouse.
4
Choose the option that best matches the intended meaning: [Expected outcome]
The equipment case _____ by lunchtime if traffic is normal.
5
Select the form that preserves the intended viewpoint and register: [Assumptive will]
_____ Noah calling; he said he'd ring around six.
6
Select the option that best expresses the stated relationship: [General possibility with can]
Regional example: Even experienced negotiators _____ the mood of a room.
7
Which form is the best fit for this context? [Specific possibility with could]
The calculation mistake _____ the result of an outdated records feed.
8
Choose the most precise completion for the sentence: [Probability phrase]
The procurement rule _____ more problems than it solves.
9
Choose the option that best matches the intended meaning: [Remote possibility]
Alternative case study: There _____ another explanation that we haven't considered.
10
Select the form that preserves the intended viewpoint and register: [Inference from absence]
He _____ in the shared studio; his access card hasn't been used today.

Degrees of certainty, deduction, possibility and expectation with modal verbs in present and future contexts

1
What is the main reason for the highlighted grammatical choice?
Regional example: The lights are on and her car is outside; she must be at home.
A.
B.
C.
2
Why is the highlighted form the best fit in this context?
Separate scenario: That can't be the final version; several sections are still missing.
A.
B.
C.
3
Which explanation best captures the effect of the highlighted form?
The supply interruption might be caused by a problem at the sorting hub.
A.
B.
C.
4
Which interpretation of the highlighted grammar is most accurate?
The signed package should arrive by lunchtime if traffic is normal.
A.
B.
C.
5
What does the highlighted structure contribute to the sentence?
That'll be Leo calling; he said he'd ring around six.
A.
B.
C.
6
What is the main reason for the highlighted grammatical choice?
Separate scenario: Even experienced negotiators can misread the mood of a room.
A.
B.
C.
7
Why is the highlighted form the best fit in this context?
The coding defect could be the result of an outdated evidence feed.
A.
B.
C.
8
Which explanation best captures the effect of the highlighted form?
The staffing policy may well create more problems than it solves.
A.
B.
C.
9
Which interpretation of the highlighted grammar is most accurate?
Regional example: There might be another explanation that we haven't considered.
A.
B.
C.
10
What does the highlighted structure contribute to the sentence?
He can't be in the regional hub; his access card hasn't been used today.
A.
B.
C.