eng8-4.1· Unit 4: Conditions & Connectors· ~13 min

First conditional

If + present, will + base (review).

The first conditional describes a real or very likely situation in the future: something that will happen IF a certain condition is met. The structure has two clauses. The if-clause (the condition) uses the present simple tense — never 'will'. The main clause (the result) uses 'will' or 'won't' followed by the base form of the verb. Either clause can come first; when the if-clause is first, a comma separates the two clauses. 'Unless' means 'if … not', so it introduces a negative condition without using 'not' a second time: 'Unless you hurry, you will miss the bus' = 'If you don't hurry, you will miss the bus'. 'When' is used instead of 'if' when the event is certain or expected rather than conditional: 'When I get home, I will call you' (getting home is certain). To avoid confusion: 'if' = possible/uncertain future; 'when' = certain/inevitable future. For example: 'If you study hard every evening this week, you will pass the exam on Friday — but unless you revise the grammar rules, you won't feel confident.'

Key terms

first conditional — A sentence structure describing a real or very likely future situation: if + Present Simple in the condition, and will + base verb in the result. For example: 'If it rains, we will stay inside.'
if-clause (condition) — The part introduced by 'if' that states the condition. It uses the Present Simple tense and never 'will'. For example: 'If you study hard, ...'.
main clause (result) — The part that states what will happen if the condition is met. It uses 'will' or 'won't' plus the base form of the verb. For example: '... you will pass the exam.'
real possibility — The meaning of the first conditional: the situation is genuinely possible or likely in the future, not imaginary. This is why it uses 'will', unlike the second conditional, which uses 'would' for unreal situations.
unless — A connector meaning 'if ... not'. It introduces a negative condition by itself, so you do not add another 'not'. For example: 'Unless you hurry, you will miss the bus' = 'If you don't hurry, you will miss the bus.'
when vs if — Use 'when' for events that are certain or expected ('When the lesson ends, we will go home'), and 'if' for events that are possible but uncertain ('If you feel sick, stay at home').
Structure of the first conditional
ClauseFormExample
if-clause (condition)if + Present Simple (never 'will')If it rains tomorrow,
main clause (result)will / won't + base verbwe will stay inside.
Usage points and variants
PointDetailExample
Real / likely futureDescribes a condition that may genuinely happen and its result.If you study hard, you will pass.
Comma placementUse a comma only when the if-clause comes first.If she studies, she will pass. / She will pass if she studies.
'unless' = if ... notIntroduces a negative condition without a second 'not'.Unless you practise, you won't improve.
'when' for certain eventsUse 'when' (not 'if') when the event is sure to happen.When the film ends, we will go out.
✎Building a first conditional (if-clause first)
  1. 1Choose the condition: Decide what must happen first: 'you / study tonight'.
  2. 2Write the if-clause in Present Simple: Put 'if' + Present Simple, with no 'will': 'If you study tonight'.
  3. 3Write the result with will + base verb: Add the result clause: 'you will pass the test'.
  4. 4Add a comma after the if-clause: Because the if-clause comes first, separate the clauses with a comma: 'If you study tonight, you will pass the test.'
✎Same idea with the result clause first
  1. 1Start with the result: Begin with the main clause using will + base verb: 'You will pass the test'.
  2. 2Add the if-clause in Present Simple: Attach the condition with 'if' + Present Simple: 'if you study tonight'.
  3. 3Use no comma: When the result clause leads, do not add a comma: 'You will pass the test if you study tonight.'
🚫Common mistake

Never put 'will' in the if-clause. The if-clause always uses the Present Simple, even though it refers to the future: write 'If it rains, ...' not 'If it will rain, ...'.

🚫Common mistake

Use 'will' or 'won't' + base verb in the result clause, not 'would'. 'Would' belongs to the second conditional for unreal situations: write 'we will stay' not 'we would stay'.

⚠️Caution

Add a comma only when the if-clause comes first: 'If she studies, she will pass.' When the result clause leads, use no comma: 'She will pass if she studies.'

⚠️Caution

'Unless' already means 'if ... not', so do not add a second 'not'. Write 'Unless you practise, you won't improve' not 'Unless you don't practise, ...', which would reverse the meaning.

Rules

  1. 1Use the present simple (not 'will') in the if-clause: 'If it rains, …' — never 'If it will rain, …'.
  2. 2Use 'will / won't + base verb' in the main (result) clause: '… we will stay at home.'
  3. 3Either clause may come first; put a comma after the if-clause only when it leads the sentence.
  4. 4'Unless' = 'if … not': 'Unless you leave now' = 'If you don't leave now'; do not add another 'not'.
  5. 5Use 'when' (not 'if') for certain or expected future events: 'When the lesson ends, we will go home.'

Practice

10 easy · 10 medium · 10 hard

10 random questions per test

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