Choose the correct sentence.

B. Unless you hurry, we will be late.

A. If you hurry unless, we will be late.

C. Unless you do not hurry, we will be late.

D. Unless you will hurry, we will be late.

Grammar rule and drill

Unless: if not, and how to use it

Unless introduces the one condition that stops something: "Unless you hurry, we will be late." The clause stays in the present simple, even about the future.

CEFR B120 questionsUpdated 5 October 2026

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Unless is a short way to say "if not". "Unless it rains, we will walk" carries the same meaning as "If it does not rain, we will walk". The word is common in warnings, rules and everyday plans.

The most common mistake is adding a second negative. Unless already gives the negative meaning, so "unless you do not hurry" means "if you do not not hurry", which is the opposite of what the speaker wants.

This page explains the present simple after unless, shows when unless and if are not interchangeable, and finishes with a 20-question drill. Every answer explains the condition in one sentence.

The rule

Unless means if not

Unless plus a positive verb equals if plus a negative verb: "Unless it rains" = "If it does not rain."
Do not add another negative: "Unless you do not hurry" is wrong.
Unless names one exception, not a general possibility.
"We will go unless it rains" means rain is the only thing that stops the trip.

Present simple after unless

The unless clause uses the present simple for future time: "Unless she calls, I will leave."
Never use will in the unless clause: "Unless she will call" is wrong.
The main clause can take will, going to, an imperative or can.
The same rule applies to when, before, after and as soon as.

Unless versus if

If opens a condition that may or may not happen: "If you come, I will be happy."
Unless removes everything except one case: "I will not come unless you invite me."
With unless, the main clause is often negative: "You cannot enter unless you have a ticket."
If unless can become if not without changing the meaning, unless is safe.

When unless does not fit

Do not use unless for a direct question: "Unless you are coming?" is wrong; use "Are you coming?"
Do not use unless for a purely imagined condition: "If I were rich" never becomes "Unless I were rich."
Use as long as for a continuing requirement: "You can stay as long as you help."
Use only if when the condition is a strict requirement: "Tickets are sold only if you book online."

Punctuation and position

The unless clause can come first or second in the sentence.
When it comes first, a comma separates the two clauses: "Unless you hurry, we will be late."
When it comes second, no comma is needed: "We will be late unless you hurry."
The same position rules apply to if, when and as soon as.

Examples

Unless you hurry, we will miss the train.The unless clause comes first and takes a comma.
I will not go unless you come with me.The negative main clause pairs naturally with unless.
Unless it rains, the match will go ahead.Unless means if it does not rain.
You cannot park here unless you have a permit.The permit is the single exception to the rule.
She will not answer unless you call her twice.The unless clause uses the present simple.
We will be late unless we leave now.No comma is needed when the unless clause comes second.
Do not call me unless it is urgent.An imperative main clause works with unless.
Unless the shop is closed, we can buy milk there.A present simple main clause describes a real possibility.
He never speaks unless someone speaks to him first.Never plus unless is a common pattern.
We play tennis on Sunday unless it rains.Unless describes the regular exception to a routine.

Common mistakes

Wrong: Unless you do not hurry, we will be late. Right: Unless you hurry, we will be late.: Unless already carries the negative meaning, so a second not reverses it.
Wrong: Unless you will come, I will go alone. Right: Unless you come, I will go alone.: The unless clause takes the present simple, not will.
Wrong: We will go unless it will rain. Right: We will go unless it rains.: Future meaning in a time or condition clause stays in the present simple.
Wrong: Unless you are rich, can you buy it? Right: Can you buy it if you are not rich?: Unless does not introduce direct questions, so the condition opens with if.
Wrong: Unless the weather, we will go. Right: Unless the weather improves, we will go.: Unless needs a full clause with a subject and a verb.

Questions learners ask

Does unless always mean if not?

In most sentences, yes. The swap works when the main clause describes what happens in every case except one: "Unless you study, you will fail" means "If you do not study, you will fail". The swap fails in imagined conditions and in questions, where unless does not belong at all.

Can I use will after unless?

No. Like other time and condition clauses, the unless clause uses the present simple even when the meaning is future: "Unless she calls, I will leave." Will goes in the main clause, not in the unless clause.

What is the difference between unless and as long as?

Unless names the single case that stops something: "We will play unless it rains." As long as names the condition that must continue for something to stay true: "You can stay as long as you help." Unless looks for the exception; as long as states the requirement.