Modal Verbs Possibility Probability

Respuesta correcta: C) It might rain later this afternoon.

• A) It may rain later this afternoon.'May' is a standard possibility form and is also acceptable here.
• B) It must rain later this afternoon.'Must' expresses strong deduction, not a fifty per cent chance.
• C) It might rain later this afternoon.'Might' suggests a lower probability than 'may'.
• D) It cannot rain later this afternoon.'Cannot' expresses impossibility.

Respuesta correcta: D) might

• A) must'Must' would assert certainty.
• B) should'Should' expresses expectation or recommendation, not the speaker's doubt.
• C) will'Will' is a future auxiliary and carries no hedging function.
• D) might'Might' conveys the speaker's own low confidence in the statement.

Respuesta correcta: B) The speaker is almost certain, based on the evidence

• A) The speaker is giving an orderAn order requires a different pattern, not this declarative use.
• B) The speaker is almost certain, based on the evidence'Must' marks a deduction from the facts given.
• C) The speaker is not certain at allThat reading would require 'might' or 'could'.
• D) The speaker is certain the opposite is true'Cannot' would express that reading instead.

Respuesta correcta: A) That cannot be true; the numbers do not match.

• A) That cannot be true; the numbers do not match.'Cannot be' expresses that the situation is impossible.
• B) That can not be true is obvious.Splitting 'cannot' and inverting the order breaks the grammar.
• C) That cannot be true is obvious.The word order after 'cannot' is inverted without cause.
• D) That cannot be being true.The progressive is not compatible with this modal use.

Respuesta correcta: B) should

• A) would'Would have' describes an unreal past result, not a reproach.
• B) should'Should have' expresses reproach about something not done in the past.
• C) can'Can have' does not carry that function.
• D) must'Must have' would express a deduction about the past, not blame.

Respuesta correcta: A) 'Could' is general ability; 'was able to' is a specific past occasion

• A) 'Could' is general ability; 'was able to' is a specific past occasion'Was able to' points to one realised instance.
• B) They mean exactly the same thing in every contextThey overlap in many sentences but differ in this focus.
• C) 'Could' is only used in questions'Could' is common in statements as well.
• D) 'Was able to' refers to the future'Was able to' is a past form.

Respuesta correcta: D) Offering a polite suggestion

• A) Issuing a strict orderAn order would use 'must' or 'have to'.
• B) Expressing a doubt about the figures'May' here softens the suggestion rather than expressing doubt.
• C) Making a prediction about the meetingNo future prediction is made in the sentence.
• D) Offering a polite suggestion'May want to' softens the advice so the listener can decide.

Respuesta correcta: C) must

• A) might'Might' would weaken a deduction the speaker considers solid.
• B) should'Should' expresses expectation, which is weaker than the evidence warrants here.
• C) must'Must be' expresses the deduction the evidence supports.
• D) will'Will' is a future auxiliary and carries no deductive meaning.

Respuesta correcta: D) He must have forgotten the appointment.

• A) He must forget the appointment.The bare infinitive refers to a present or future obligation.
• B) He will have forget the appointment.The future perfect requires a participle, not the base form.
• C) He must been the appointment.That sequence is not grammatical.
• D) He must have forgotten the appointment.'Must have' plus participle marks a firm conclusion about the past.

Respuesta correcta: A) 'To' must be removed after 'must'

• A) 'To' must be removed after 'must'Modal verbs are followed directly by the base form.
• B) Nothing is wrong with the sentenceThe infinitive after 'must' is a standard error.
• C) 'Must' must be 'will'Neither modal takes an infinitive, so that change would not fix it.
• D) 'Leave' must be 'leaving'After a modal the base form is required, not the -ing form.

Respuesta correcta: D) would

• A) will'Will rather' is not a standard construction.
• B) must'Must' expresses obligation, not preference.
• C) could'Could rather' is not idiomatic in this position.
• D) would'Would rather' expresses a preference between two options.

Respuesta correcta: C) Students have to wear a uniform at this school.

• A) Students must to wear a uniform at this school.No infinitive may follow a modal verb.
• B) Students are having to wear a uniform to school.The progressive is not used with 'have to' in this meaning.
• C) Students have to wear a uniform at this school.'Have to' marks an externally imposed obligation.
• D) Students have wear a uniform at this school.'Have' requires the base form, not the bare infinitive.

Respuesta correcta: A) There is a chance that all tickets have been sold

• A) There is a chance that all tickets have been sold'May' keeps the possibility open without confirming it.
• B) All tickets have certainly been soldCertainty would require 'must be' or a plain statement.
• C) No tickets have been sold'Cannot be sold out' would express that reading.
• D) The concert has been cancelledNo mention of a cancellation appears in the sentence.

Respuesta correcta: C) should

• A) must'Must have' would turn the recommendation into a deduction.
• B) can'Can have' does not express advice.
• C) should'Should have seen' is a recommendation about what ought to have happened.
• D) will'Will have' is a future perfect form with no advisory sense.

Respuesta correcta: B) I would a cup of coffee like.

• A) I would like a cup of coffee.The fixed expression 'would like' is complete here.
• B) I would a cup of coffee like.The auxiliary 'would' cannot be separated from 'like'.
• C) I would like to have a cup of coffee.'Would like to' plus the infinitive is correct.
• D) I would like a coffee cup.'Would like' plus a noun phrase is also correct.

Respuesta correcta: C) Obligation or advice, close to 'should'

• A) Past obligation only'Ought to have' covers the past, but the plain form is present.
• B) Certainty about the pastThat is 'must have'.
• C) Obligation or advice, close to 'should''Ought to' is the formal equivalent of 'should'.
• D) Probability of about fifty per centThat is 'may' or 'might'.

Respuesta correcta: D) must

• A) should'Should not' would express advice rather than a prohibition.
• B) might'Might not' expresses a low probability, not a rule.
• C) could'Could not' expresses inability rather than prohibition.
• D) must'Must not' expresses a prohibition grounded in a rule.

Respuesta correcta: B) We should have left earlier to avoid the traffic.

• A) We should leave earlier to avoid the traffic.The bare 'should' refers to the present or future.
• B) We should have left earlier to avoid the traffic.'Should have' expresses a past obligation that was not met.
• C) We will have left earlier to avoid the traffic.The future perfect refers to a future reference point.
• D) We must have left earlier to avoid the traffic.'Must have' would express a deduction, not an obligation.

Respuesta correcta: A) Ability that exists in one direction but not the other

• A) Ability that exists in one direction but not the other'Can' grants the skill and 'cannot' withholds it in writing.
• B) A possibility that depends on time'Can' expresses ability here, not a temporal condition.
• C) A prohibition on writingProhibition would require a modal of obligation, not 'cannot' as ability.
• D) A deduction about the pastPast deduction requires 'must have'.

Respuesta correcta: B) You might want to reconsider the offer.

• A) You might wanting to reconsider the offer.The -ing form cannot follow a modal verb.
• B) You might want to reconsider the offer.'Might' hedges the suggestion politely and is fully standard.
• C) You might to reconsider the offer.No infinitive marker may follow a modal.
• D) You might reconsiders the offer.The base form must follow the modal.