connector + condition clause, + main clauseWhen the condition clause comes first, separate it from the main clause with a comma.
Condition Clauses
B1Condition clauses show what must happen first: if, unless, provided that, as long as. Choose the connector by meaning, and use a comma when the condition comes first.
What you'll learn
- Use if for a neutral condition.
- Use unless to mean except if.
- Use provided that for a strong or formal condition.
- Use as long as to mean only if this condition is true.
- Add a comma after a fronted condition clause.
Structure
main clause + connector + condition clauseWhen the condition clause comes second, no comma is needed before it in standard short sentences.
Build a sentence
Connector
Meaning
ifneutral condition
If Anna calls, I'll text you.
Use if for a basic condition with no extra meaning.
When to use
Rules and permissions
Use provided that and as long as in rules, promises, and permissions: You can go provided that you finish the report.
Warnings
Use unless when one negative condition blocks a result: Unless you leave now, you'll miss the train.
Everyday planning
Use if for ordinary choices and plans: If Anna calls, tell her I'm in a meeting.
Markers
ifunlessprovided thatas long as
In contrast
vs first-conditional
Condition clauses are connectors. First Conditional is one full pattern that often uses them: If + present, will + base verb.
Common mistakes
Wrong
Unless you don't hurry, you'll miss the bus.
Correct
Unless you hurry, you'll miss the bus.
Unless already includes the negative idea except if. Do not add another not unless you want a different meaning.
Wrong
If you don't book now, you won't get a seat.
Correct
Unless you book now, you won't get a seat.
The meaning is except if you book now, so unless fits better than if.
Wrong
Unless you need help, call me.
Correct
If you need help, call me.
This is a simple positive condition, not an except-if meaning, so use if.
Wrong
If Tom calls me tell him I'm busy.
Correct
If Tom calls me, tell him I'm busy.
A fronted condition clause is followed by a comma before the main clause.
Common misconceptions
❝ Unless is only for bad results. ❞
Unless gives an exception, not a bad result. The result can be positive or negative: Unless Maria objects, we'll start now.
❝ As long as only talks about time length. ❞
As long as can mean only if in condition clauses: You can stay as long as you keep quiet.
Skills in this rule (6)
USE_IF_FOR_A_CONDITIONw5Use if to introduce a condition
Use if when one situation depends on another. The if-part gives the condition before the result happens.
USE_UNLESS_FOR_EXCEPT_IFw5Use unless to mean except if
Use unless for the negative idea except if. It means the result happens in every case except one.
USE_PROVIDED_THAT_FOR_A_STRONG_CONDITIONw3Use provided that for a strong formal condition
Use provided that when the condition is strict or official. It often appears in rules, offers, and permissions.
USE_AS_LONG_AS_FOR_ONLY_IFw4Use as long as to mean only if this condition is true
Use as long as when one action is allowed or possible only under a condition. It often sounds like a limit or requirement.
COMMA_AFTER_FRONTED_CONDITIONw4Use a comma after a condition clause at the beginning
When the condition clause comes first, add a comma before the main clause. No comma is needed when the condition clause comes second.
CHOOSE_CONNECTOR_BY_MEANINGw5Choose the connector that matches the meaning
Pick if for a neutral condition, unless for except if, provided that for a strong formal condition, and as long as for only if. Focus on meaning, not just position.