Where it appears in the exam
What is it?
Permission modals (can, may, be allowed to) express what is permitted or forbidden. In English, REGISTER matters as much as meaning: can is informal, may is formal, be allowed to describes written rules. Cambridge doesn't test whether you know what 'permission' means -- it tests whether you choose the right form for the context.
Why it matters in the exam
Part 4 (Transformations) is the flagship format for this competency: Cambridge asks you to rephrase 'you can't' as 'you are not allowed to' constantly. In Part 2, you must produce 'allowed' or 'permitted' without options. Register determines the answer.
The cognitive trap
"Can I leave? / May I leave? / Am I allowed to leave?"
Your brain defaults to 'can' for all permission requests. Most learners have one automatic form regardless of formality -- they never pause to calibrate register.
"Can I leave?" (informal) is not "May I leave?" (formal) is not "Am I allowed to leave?" (rule-based)
3 forms for the same permission. Cambridge chooses the correct one by context and register, not by meaning. Your instinct to always reach for 'can' is exactly what the exam exploits.
Recognition pattern
In the exam, look for the key signal first. The answer follows.
Register and context signals
"You can borrow my car if you want."
"Could I possibly use your phone?"
"Passengers may carry one item of hand luggage."
"You can't park here."
"Phones are not allowed in the exam room."
"are not allowed to take photographs"
"don't let visitors enter"
Register and structure errors
"Can I borrow your pen for a moment?" (in a formal letter / interview)
Can I = informal request. In formal contexts (letter, interview, academic), Cambridge expects may or could. In everyday conversation, can is perfectly fine.
"May I borrow your pen for a moment?"
May I = formal/polite request. A social context requiring courtesy.
"You are not allowed taking photographs."
'Allowed to' ALWAYS takes an infinitive with to, NEVER -ing. A very common structural error.
"You are not allowed to take photographs."
Be allowed to + infinitive. Correct passive structure.
"The teacher doesn't let us to use dictionaries."
Let NEVER takes 'to'. It's a bare infinitive: let + someone + verb. Error by analogy with 'allow someone to'.
"The teacher doesn't let us use dictionaries."
Let + object + bare infinitive. 'Let us use', not 'let us to use'.
Why your brain gets it wrong
The learner's short circuit
Analyse the trap by exam format
Visitors are not ______ to enter the building after 6pm without prior authorisation.
Your brain reaches for 'able' (capable). But this isn't ability -- it's a rule. 'Not allowed to' = not permitted. 'Not able to' = not capable (different meaning).
not _____ to enter
'after 6pm without authorisation' = rule/regulation = allowed, not able.
→ allowed
Allowed (permission) vs Able (ability)
Both structures are 'be + ___ + to + infinitive'. But allowed = permission and able = capacity. The context (rule vs capability) decides.
Strategy
Read the context: is there a rule/regulation/authority? Then allowed. Is there a capacity/ability? Then able.
Students are not allowed to use calculators during the exam. (LET) The school doesn't ______ during the exam.
You know 'let' needs an object. But you add 'to' by analogy with 'allow to'. Let + object + bare infinitive. Never 'let someone to do'.
LET
Let = bare infinitive (no to). Allow = infinitive with to. Different structures for the same meaning.
→ let students use calculators
Let and allow have opposite structures
Allow someone TO do vs Let someone DO. Same meaning, different structure. Cambridge exploits this difference in Part 4.
Strategy
LET then bare verb (let him go). ALLOW then to + infinitive (allow him to go). Memorise them as pairs.
Hotel guests 5 use the spa facilities free of charge during their stay.
Your brain picks 'can' because it's the most automatic permission modal. But the context is a hotel announcement (formal register). 'May' is the formal permission modal. 'Could' asks for permission, it doesn't grant it. 'Might' is possibility.
The register of the text decides between can and may
Both grant permission. But Cambridge wants you to choose by REGISTER: formal/institutional texts = may. Informal conversation = can.
Strategy
Read the TONE of the text. Hotel, airport, regulation, announcement? Then may. Friend, family, casual? Then can.
Permission & Prohibition is 1 of 82
The exam tests 82 grammar competencies across 19 families. Mastering one is the first step. Automating all 82 is passing.
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