Where it appears in the exam
What is it?
The bare infinitive is the verb without 'to': go, wait, do (not 'to go', 'to wait', 'to do'). It is obligatory after all modals (can/must/should/will/might), after 'let' (let me GO), after 'make' in the active (made him WAIT), and after 'had better' (you'd better LEAVE). The B2 challenge: 'make' in the PASSIVE recovers the 'to' — 'He was made TO wait'. And 'let' has NO passive: it transforms into 'be allowed to'.
Why it matters in the exam
Part 4 is the star territory for this competency. Cambridge asks you to transform between 'allow + to' and 'let + bare infinitive', or between 'make' active (without to) and 'make' passive (with to). Each extra or missing 'to' costs you the entire question. In Part 2, a gap asking for 'let' or 'make' may also appear, where the bare infinitive that follows is your signal to identify the structure.
The cognitive trap
"The instinct: "Let me to go" / "Can to do" / "Made him to wait""
Why your brain does this: in most languages, the infinitive is always the same form. There is no 'with to' vs 'without to' distinction. Your brain adds 'to' everywhere by default because it only knows one infinitive form.
"Let me go" ✓ / "Let me to go" ✗ — "Can do" ✓ / "Can to do" ✗
The English rule: there are TWO infinitives — the full infinitive (to go) and the bare infinitive (go). Your brain doesn't distinguish between them because most languages only have one. The result: you add 'to' where it doesn't belong (can to do) or remove it where it's needed (was made wait).
Recognition pattern
In the exam, look for the key signal first. The answer follows.
Recognition signals
"She can ___ several languages." → 'speak' (not 'to speak')
"Please let me ___ my point." → 'finish' (not 'to finish')
"The film made me ___ about my childhood." → 'think' (not 'to think')
"He was made ___ for two hours." → 'to wait' (WITH 'to')
"You'd better ___ now." → 'leave' (not 'to leave')
"allowed us TO go" → "let us go" (no to)
"She helped me carry / to carry the bags." — Cambridge accepts both.
Mistakes Cambridge exploits
"I saw him to leave the building."
Your brain adds 'to' by inertia. But perception verbs follow the same rule as 'let' and 'make': object + bare infinitive. 'Saw him leave', not 'saw him to leave'.
"I saw him leave the building."
After perception verbs (see, hear, watch, feel, notice) + object, the infinitive takes no 'to'. Same pattern as 'let' and 'make'.
"The teacher made us to repeat the exercise."
'Make' in the active works like 'let': object + bare infinitive. The 'to' doesn't belong. Your brain adds it by default because one-infinitive languages don't distinguish.
"The teacher made us repeat the exercise."
Make + object + bare infinitive in active voice. No 'to'.
"She helped me carrying the boxes."
'Help' accepts bare infinitive or full infinitive, but NEVER a gerund. 'Helped me carrying' is incorrect. The pattern is 'help + object + (to) + base verb'.
"She helped me carry the boxes."
'Help' accepts bare infinitive or full infinitive ('helped me carry' and 'helped me to carry' are equally correct). Cambridge accepts both forms.
"You'd better to leave before it gets dark."
'Had better' behaves like a modal — bare infinitive obligatory. The error occurs because 'to' sounds natural after 'better' by analogy with 'it's better to leave'.
"You'd better leave before it gets dark."
Had better + bare infinitive. Functions as a semi-modal.
"You must to study harder for the exam."
Learners add 'to' because 'must to study' feels complete. In English, no modal accepts 'to': can go, must go, should go — always bare infinitive.
"You must study harder for the exam."
Modal + bare infinitive. All modals follow this rule without exception.
Why your brain gets it wrong
The learner's short circuit
Analyse the trap by exam format
They don't allow visitors to take photographs inside the museum. They don't ______ photographs inside the museum. (LET)
Your brain copies 'to take' from the original sentence and pastes it after 'let'. The pattern 'allow + to' is fresh in your working memory and contaminates the transformation.
LET
Keyword LET = bare infinitive obligatory. Remove the 'to' from the original sentence.
→ let visitors take
Allow → let = remove 'to'
Cambridge knows you just read 'allow... to take' and your brain will copy the 'to'. The transformation requires you to consciously remove it.
Strategy
When you see keyword LET: write the transformation, review, and CROSS OUT any 'to' between the object and the verb. 'Let' + object + verb (bare). Always.
The coach made the players train for three extra hours. The players ______ for three extra hours. (MADE)
You've learned the rule 'make + bare infinitive' and apply it in the passive too. But the passive of 'make' is the ONLY exception: it recovers the 'to'. Your brain generalises the rule without the exception.
MADE
'Were made' = passive of make. In the passive, the infinitive RECOVERS its 'to'. Active: made them train. Passive: were made TO train.
→ were made to train
The exception to the exception
Make is the double trap: first you learn it takes NO 'to' (active), then you discover it DOES take 'to' (passive). Cambridge tests both directions.
Strategy
Check the voice: does the subject DO the action (active) or RECEIVE it (passive)? Active: 'made them train' (no to). Passive: 'were made TO train' (with to).
The security guard didn't 7 us enter the building without showing our identification cards.
Your brain produces 'allow' — correct in meaning, but 'allow' needs 'to' ('allow us TO enter'). The gap is followed by 'us enter' (bare infinitive, no 'to'). Only 'let' works with a bare infinitive.
The structure decides, not the meaning
Allow, let, permit — all three mean 'permit'. But the GRAMMAR that follows distinguishes them. If you see a bare infinitive after the gap → only 'let' fits.
Strategy
In Part 2, read AFTER the gap. Do you see 'object + verb without to'? → 'let'. Do you see 'object + to + verb'? → 'allow/permit'. The post-gap structure decides.
Bare Infinitive (after modals/let/make) is 1 of 82
The exam tests 82 grammar competencies across 19 families. Mastering one is the first step. Automating all 82 is passing.
Related competencies