Bare Infinitive vs To-Infinitive Explained
Nova
AI Writer at ESL Brains
A2 students confuse bare and to-infinitive forms after modals and verbs. Clear examples, common errors, and classroom activities to teach the difference.
This article was written by Nova, an AI author — it belongs to the AI-generated side of the ESL Brains blog. Prefer human-made materials? Browse the lesson library — every lesson plan is created by the ESL Brains team.
Your A2 student says ‘I can to swim well’ when talking about hobbies. Another insists ‘I want go home now’ sounds correct. The bare infinitive and to-infinitive distinction trips up learners who’ve spotted different patterns but can’t work out which verb takes which form.
TL;DR
- Bare infinitive (go, eat, work) follows modal verbs like can, must, and should.
- To-infinitive (to go, to eat, to work) follows verbs like want, need, and decide.
- Students commonly add ‘to’ after modals or drop ‘to’ after verbs that require it.
- Visual contrast activities help students notice and practise the two patterns correctly.
What is the difference between bare infinitive and to-infinitive?
The bare infinitive is the base verb form without ‘to’, whilst the to-infinitive adds ‘to’ before the base form. Kaplan International’s grammar guide confirms this basic distinction that causes confusion for learners.
The difference determines which verbs can follow each pattern. After modal verbs, you’ll always find the bare form: ‘She can dance’, ‘You must leave’. After many common verbs, the to-infinitive is required: ‘I want to dance’, ‘She decided to leave’.
Your students need to recognise these two distinct grammatical environments. The form doesn’t change the meaning of the main verb — ‘dance’ means the same thing in both cases — but the grammar rules are fixed.
Bare infinitive structure
The bare infinitive uses the base verb form with no ‘to’ marker. Examples include ‘I can swim’, ‘She must go’, and ‘They should study’. This pattern appears after specific verbs that signal the bare form is required.
You’ll spot bare infinitives most commonly after modal verbs. The structure never varies: modal + bare infinitive. ‘Can swim’, ‘will arrive’, ‘must finish’ — no ‘to’ appears anywhere.
In this A2 lesson on bare infinitive vs to-infinitive, students practise recognising this pattern through cultural scenarios that make the grammar choice meaningful.
To-infinitive structure
To-infinitive always follows the pattern ‘to’ + base form. Clear examples are ‘I want to swim’, ‘She needs to go’, and ‘They decided to study’. The ‘to’ is essential — dropping it creates an error.
Most main verbs in English take the to-infinitive when followed by another verb. This makes it the more common pattern, which explains why students sometimes overgeneralise it to contexts requiring bare infinitive.
The to-infinitive also expresses purpose: ‘I went to buy bread’, ‘She called to apologise’. This meaning-use helps students remember the form in communicative contexts.
| Bare Infinitive | To-Infinitive | Example Sentence |
|---|---|---|
| can + swim | want + to swim | ’I can swim but I want to swim faster’ |
| must + go | need + to go | ’You must go and she needs to go too’ |
| should + study | decide + to study | ’We should study or decide to study later’ |
| will + help | plan + to help | ’I will help and plan to help more’ |
When do we use the bare infinitive?
Use bare infinitive after modal verbs and causative verbs — two specific verb categories that never take ‘to’ before the following verb. These contexts are fixed; there’s no choice involved.
Modal verbs form the largest group requiring bare infinitive. Students who master this pattern eliminate most bare infinitive errors. Causative verbs represent a smaller but important group for natural-sounding English.
After modal verbs
Modal verbs — can, could, will, would, shall, should, may, might, must — always take bare infinitive. Never add ‘to’ after these verbs. ‘She can dance’ is correct; ‘She can to dance’ is wrong.
The rule applies without exception. Whether expressing ability (can), obligation (must), or possibility (might), the pattern stays consistent. This reliability helps students once they’ve grasped the modal category.
Your A2 students will use modals frequently for everyday communication. Focus on the most common ones first: can, will, should, must. These cover ability, future plans, advice, and necessity — all high-frequency functions.
After causative verbs
Causative verbs — let, make, and have (in causative use) — take bare infinitive. Examples include ‘Let me help’, ‘Make him stop’, and ‘I’ll have someone fix it’. Students often add unnecessary ‘to’ here.
The causative make differs from the regular verb make. ‘I make dinner’ uses make as a main verb. ‘I make him cook dinner’ uses causative make + bare infinitive. This distinction matters for accurate production.
Let appears in polite requests and permissions: ‘Let me check’, ‘Let us know’. This A2 lesson on bare infinitive vs to-infinitive includes natural contexts where students practise these forms.
| Verb Category | Examples | Sample Sentence |
|---|---|---|
| Modals | can, must, will, should | ’You can speak three languages’ |
| Causatives | let, make, have | ’Let me carry your bag’ |
| Perception | see, hear, watch | ’I saw him leave the building’ |
When do we use the to-infinitive?
Use to-infinitive after most main verbs and to express purpose. This pattern covers a much wider range of verbs than bare infinitive, making it the default choice when in doubt.
BBC Learning English reference notes that to-infinitives appear in many common contexts, making them essential for A2-level communication.
After common verbs
Common verbs like want, need, decide, plan, hope, try, and learn always require to-infinitive. The ‘to’ is grammatically necessary — dropping it produces errors like ‘I want go home’.
These verbs express intentions, desires, and mental states that naturally connect to future actions. ‘I want to travel’, ‘She decided to study’, ‘We hope to arrive early’. The to-infinitive makes this future connection explicit.
At A2 level, prioritise the most frequent verbs: want, need, like, decide, try. These cover daily communication needs and appear in most elementary coursebooks. Build accuracy with these before introducing less common options.
To express purpose
To-infinitive answers the question ‘why?’ — it explains the purpose of an action. ‘I went to buy bread’ explains why you went out. ‘She called to apologise’ explains why she made the phone call.
This purpose meaning helps students remember the form. When they can explain the reason behind an action, to-infinitive feels natural. ‘I’m studying English to get a better job’ makes perfect sense to most learners.
Purpose expressions work well for speaking practice. Students can discuss their goals, travel plans, or daily activities using to-infinitive naturally.
| Verb | Example with To-Infinitive | Purpose Example |
|---|---|---|
| want | ’I want to learn Spanish' | 'I went to see my friend’ |
| need | ’She needs to finish work' | 'We stopped to buy petrol’ |
| decide | ’They decided to move house' | 'He called to book a table’ |
| try | ’We try to exercise daily' | 'She opened it to check inside’ |
What are the most common student errors?
A2 students make two main errors: adding ‘to’ after modals and dropping ‘to’ after main verbs. Both stem from pattern confusion rather than meaning problems.
These errors are systematic, not random. Students who produce ‘I can to swim’ have spotted that English often uses ‘to’ before verbs. They’re applying a real pattern in the wrong context.
Adding ‘to’ after modals
Wrong: ‘I can to swim’, ‘She must to go’, ‘We should to study’. Right: ‘I can swim’, ‘She must go’, ‘We should study’. Students overgeneralise the to-infinitive pattern because it’s more common overall.
This error affects all modals equally. You’ll hear ‘can to’, ‘will to’, ‘must to’ — the student has learned that ‘to’ often precedes verbs but hasn’t grasped the modal exception.
Address this with explicit contrast. Show ‘I can swim’ next to ‘I want to swim’ on the board. Point out that can is a modal; want is not. The verb type determines the pattern.
Missing ‘to’ after main verbs
Wrong: ‘I want go home’, ‘She needs study more’, ‘We decided leave early’. Right: ‘I want to go home’, ‘She needs to study more’, ‘We decided to leave early’. Students transfer the modal pattern incorrectly.
This error often appears after the student has learned modals well. They’ve mastered ‘I can go’ and wrongly extend this to ‘I want go’. It’s actually a sign of partial progress — they’re using English patterns, just in the wrong places.
Drill the contrast explicitly. After practising ‘I can help’, immediately practise ‘I want to help’. Make the difference audible and visible.
| Common Error | Correction | Why It Happens |
|---|---|---|
| ’I can to swim' | 'I can swim’ | Overgeneralising to-infinitive pattern |
| ’I want go home' | 'I want to go home’ | Applying modal pattern to main verbs |
| ’Let me to help' | 'Let me help’ | Adding ‘to’ after causative verbs |
| ’She must to finish' | 'She must finish’ | Treating modals like main verbs |
How can you teach this grammar point effectively?
Start with noticing activities before moving to controlled practice. Students need to spot the two patterns consciously before they can produce them accurately.
ESL Brains publishes 1,000+ video-based lesson plans covering A1 to C2 levels, many incorporating grammar points like infinitives through authentic communicative contexts rather than isolated drills.
Noticing activities
Sentence sorting works well for pattern recognition. Give students mixed sentences containing both patterns: ‘I can swim’, ‘I want to swim’, ‘She must go’, ‘She needs to go’. Ask them to group sentences by pattern, not meaning.
Highlight and categorise exercises build awareness. Students read a short text and highlight all infinitives in two colours — one for bare, one for to-infinitive. Then they categorise the verbs that came before each type.
This A2 lesson on bare infinitive vs to-infinitive uses cultural scenarios where students naturally encounter both patterns in meaningful contexts, making the grammar choice relevant to communication.
Controlled practice
Gap-fill exercises provide focused practice. Create sentences with missing ‘to’ where students decide whether to add it or leave it blank: ‘I can ___ speak French’, ‘I want ___ learn German’.
Error correction tasks develop recognition and repair skills. Give students sentences containing typical A2 errors and ask them to find and fix the mistakes. Include both error types: unnecessary ‘to’ and missing ‘to’.
Guided sentence building moves towards production. Give prompts like ‘can / she / dance’ and ‘want / she / dance’ for students to build complete sentences. The contrast becomes clear through construction.
| Activity Type | Example | Student Task |
|---|---|---|
| Sorting | Mixed sentences on cards | Group by bare vs to-infinitive pattern |
| Error correction | Text with typical mistakes | Find and correct infinitive errors |
| Gap-fill | ’I must ___ finish’ | Add ‘to’ or leave blank |
| Guided building | ’can / swim / I’ | Construct complete sentence |
Never rush the controlled stage. Students need multiple encounters with clear right answers before attempting free production. A solid foundation here prevents fossilised errors later.
Build speaking activities around the structures they’ve practised. Use topics that naturally generate both modals and common main verbs — abilities and future plans work perfectly for A2 level.
Frequently Asked Questions
What is the difference between bare infinitive and to-infinitive?
Bare infinitive is the base verb form without ‘to’ (swim, go, eat) used after modals. To-infinitive adds ‘to’ before the verb (to swim, to go, to eat) and follows verbs like want, need, and decide.
When do we use the bare infinitive in English?
Use bare infinitive after modal verbs (can, must, should, will) and causative verbs (let, make). For example: ‘I can swim’ or ‘Let me help you’.
Is ‘to’ always used with the infinitive?
No, ‘to’ is not always used. Modal verbs take bare infinitive without ‘to’, whilst other verbs like want, need, and decide require to-infinitive with ‘to’.
What are examples of bare infinitive sentences?
Common examples include: ‘She can dance well’, ‘You must finish homework’, ‘Let him speak’, and ‘They should arrive soon’. Notice no ‘to’ appears before the main verb.
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Ready to teach bare infinitive vs to-infinitive with confidence? This A2 lesson on bare infinitive vs to-infinitive walks students through both patterns using cultural scenarios that make the grammar meaningful. The 60-minute lesson includes video input, controlled practice, and speaking activities.