To- & Bare Infinitives

Here's a tiny word that causes a surprising amount of trouble: to. Should you write "I can to swim" or "I can swim"? "You must to go" or "You must go"? Your ear isn't always sure, because English uses the plain form of a verb in two slightly different outfits — one with to in front and one without — and there's no obvious signal telling you which is coming. The good news is that the rule behind it is short and reliable, and once you've got it, that little to stops being a guessing game.

The infinitive is the base form of a verb — go, eat, play. Sometimes it takes to in front (to go), and sometimes it doesn't (go). Knowing which is which keeps your verbs sounding right, and it's one of those details that quietly marks careful writing.

The to-infinitive

Most of the time, the infinitive comes with to:

I want to go. · She hopes to win. · It's time to leave.

You use the to-infinitive after lots of common verbs (want, hope, need, decide, try, promise, learn), after adjectives (happy to help, ready to start, hard to explain), and to show purpose — the reason you did something: I came to see you, She phoned to say thanks. That last job is really handy, because it lets you answer "why?" in a single tidy phrase instead of a whole extra clause.

The bare infinitive (no "to")

A few situations drop the to, and they're worth learning as a set:

• After modal verbs: I can swim. You must go. She should rest. (never "can to swim")
• After let and make: Let me try. She made me laugh.
• After "help" (optional): Help me (to) carry this. Both are fine here.

The pattern

• After a modal (can, must, will, should, might...) → no "to".
• After let or make → no "to".
• Most other times → use "to".

Two families, then: the small "no-to" club (modals plus make and let), and everything else, which takes to. If you can remember the short club, the to takes care of itself the rest of the time.

A quick test when you're stuck

If you're unsure, look at the word right before the gap. Is it a modal like can, will, must or should? Then no to. Is it make or let with a person after it? Then no to. Anything else — an ordinary verb like want or decide, an adjective like glad, or a reason you're doing something — almost always takes to. Running that one check saves you from the most common slips before they reach the page.

Watch out — modals never take "to"

✗ You must to go. → ✓ You must go. ✗ She can to sing. → ✓ She can sing. ✗ We should to leave now. → ✓ We should leave now.

This is the number-one infinitive mistake, and it's an easy one to hunt down when you check your work: whenever you see a modal, make sure no stray to has crept in after it.

Watch out — make and let don't take "to" either

✗ My dad made me to tidy my room. → ✓ My dad made me tidy my room. ✗ She let me to borrow it. → ✓ She let me borrow it.

Careful, though — verbs that mean something similar to make and let, like force, allow and tell, do take to: She allowed me to go, He told me to wait. Only make and let drop it. This catches people out, so it's worth a second glance.

More worked examples

• ✓ I need to finish my homework. (after need → to)
• ✓ You must hand it in tomorrow. (after a modal → no to)
• ✓ We stayed late to help clear up. (showing purpose → to)
• ✓ Let me explain. (after let → no to)
• ✗ I'm happy help. → ✓ I'm happy to help. (after an adjective → to)

Why English bothers with two forms

It might seem fussy that English has both to go and plain go, but there's a quiet logic to it. The modals — can, must, will, should and the rest — are already a kind of helper verb, and they carry the grammatical weight themselves, so the verb after them can stay in its barest form: can go, must leave. Adding to would just be clutter, which is why it feels wrong to your ear. Make and let work in a similar way — they're strong, direct verbs about causing or allowing something, and they attach straight to the verb without a to getting in the way. Everywhere else, the to acts like a small bridge, linking the first verb to the action that follows: want to go, hope to win, decided to leave. You don't need to remember this reasoning to use the forms correctly, but seeing the pattern makes it stick, and it explains why the "no-to" club is such a short, tight little group. Learn the members of that club, and the bridge takes care of itself the rest of the time.

Why it matters

Infinitives turn up in almost every sentence you write, so getting the little to right (or leaving it out at the right moment) keeps your writing smooth and correct. The modal slip — "must to go" — is one that examiners spot instantly, and fixing it is one of the quickest ways to make your English look more assured. Better still, the rule is so short that it becomes automatic fast: a few days of noticing it, and you'll stop even thinking about it. That's the best kind of grammar point — a small effort now for a lasting, silent gain.

Quick check

To or no "to"?

1. I need ___ (finish) this.

2. You should ___ (rest).

3. Let me ___ (help).

4. She wants ___ (learn) guitar.

5. My mum made me ___ (wash) up.

6. We can ___ (start) whenever you like.

Where next

• Gerund or Infinitive? — -ing vs to after verbs.
• Modal Verbs Overview — the modals that drop "to".
• Present Participles (-ing forms) — the -ing form.