The first conditional talks about a real, possible future — something that might happen, and what will follow if it does.
The structure splits the sentence into two clauses:
The if-clause sets the condition. The main clause says what follows. The condition uses the present simple even though you're talking about the future — this is the single most important rule of the form, and the one learners break most often.
Form
| CLAUSE | VERB FORM | EXAMPLE |
|---|---|---|
| if-clause | present simple | If you study |
| main clause | will + base verb | you will pass |
Contractions are normal in speech and informal writing: I'll, you'll, she'll, we'll, they won't.
The negative goes on whichever verb carries the meaning:
Questions work the same way — the main clause takes question form, the if-clause stays statement-shaped:
Use
The first conditional describes one specific future event, not a general truth. The speaker thinks the condition is realistic — it might actually happen.
Typical contexts are plans, predictions, warnings, promises, and deals.
Plans. If Maria comes, we'll order pizza.
Warnings. If you touch that, you'll burn yourself.
Promises. I'll call you if I hear anything.
Deals. If you wash the dishes, I'll cook dinner.
Order of clauses
Both orders are correct, and the meaning is identical.
When the if-clause comes first, put a comma after it. When the main clause comes first, no comma is needed.
Main clause alternatives
Will is the default, but the main clause can take other verbs to shade the meaning.
may, might, could — lower certainty. The result is possible, not guaranteed.
should — advice or recommendation.
can — ability or permission.
Imperative — direct instruction that depends on the condition.
be going to — works like will, with a slight emphasis on a plan or a visible outcome.
First conditional vs zero conditional
The two forms look similar but carry different meanings.
Zero conditional describes what is always true — a rule, a law of nature, a habit. Both clauses use the present simple.
First conditional describes one specific future event — something that might happen once.
The first sentence is about every time, everywhere. The second is about this afternoon, this kettle, this cup of tea.
A useful test: if the sentence could start with "Every time…" and still mean the same thing, it's zero conditional. If it's about one particular moment in the future, it's first.
A note on alternatives to "if"
Words like unless, as long as, as soon as, and when can replace if with shifts in meaning — these are covered separately.
Common mistakes
Will in the if-clause
Past tense in the if-clause
Negation on the wrong clause
Missing comma when the if-clause is first
Confusing first and zero conditional