English Conditionals: Zero, First, Second, Third & Mixed

English conditionals help you connect a condition with its result: facts, plans, imagined situations and past regrets. The verb forms matter, but meaning comes first. Choose the timeline and how real the situation feels; the correct pattern usually follows.

English conditionals comparison chart

Type	Main meaning	Usual pattern	Example
Zero	general result or rule	if + present, present	If a password is weak, hackers guess it more easily.
First	realistic future possibility	if + present, will + base verb	If the train is late, I will call you.
Second	imaginary or unlikely present/future	if + past, would + base verb	If I worked fewer hours, I would exercise more.
Third	imaginary past and past result	if + past perfect, would have + participle	If we had booked earlier, we would have paid less.
Mixed	imaginary condition and result in different times	past perfect + would, or past + would have	If I had slept well, I would feel better now.

These are useful learning patterns rather than four boxes that contain every possible sentence. Speakers also use can, could, may, might, should and imperatives when those meanings fit.

Zero conditional: a regular result

Use zero conditional when one situation regularly produces another. It covers scientific facts, routines, instructions and rules.

Form: if/when + present simple, present simple

• If you press this button, the screen turns off.
• When our lesson finishes early, we review vocabulary.
• If people do not water these plants, they die.

When often works when the result is expected every time. If leaves the condition more open. You can also give an instruction: “If the alarm sounds, leave the building.”

First conditional: a real future possibility

Use first conditional when you consider a future condition possible. The if-clause uses a present form even though its meaning is future.

Form: if + present simple, will + base verb

• If the weather improves tomorrow, we will hold the event outside.
• I will send the notes if you miss the class.
• If she finishes before six, she can join us for dinner.

Do not put will in an ordinary future condition: write “If the supplier calls, I will answer,” not “If the supplier will call.” The result can use another modal or an imperative: “If you need help, ask”; “If we leave now, we might catch the earlier train.”

Second conditional: an unreal or distant idea

Use second conditional for an imaginary, impossible or unlikely situation in the present or future. The distance is the speaker’s judgement, not a mathematical probability.

Form: if + past simple, would + base verb

• If I lived closer, I would walk to work.
• What would you change if you were the manager?
• If the apartment had a balcony, we could grow herbs.

In formal and careful English, were is common for all persons in hypothetical clauses: “If I were you …” and “If she were here …”. Was also occurs in informal speech, especially with I, he, she and it. A test may expect were in the fixed advice phrase “If I were you.”

First or second: the speaker’s view

Compare one event:

• If I get the job, I will move to Berlin. The speaker treats getting it as a real possibility.
• If I got the job, I would move to Berlin. The speaker imagines the result but presents the condition as more remote.

Both can discuss the future. The tense form changes how the speaker frames the chance.

Third conditional: a different past

Use third conditional to imagine changing a past event and its past result. The real events are already finished.

Form: if + past perfect, would have + past participle

• If I had saved the document, I would not have lost my work.
• We would have arrived on time if we had taken the earlier bus.
• If they had explained the fee, I might have chosen another plan.

The sentence does not state the real story directly, but it implies it. “If I had saved the document …” suggests that I did not save it. “I would not have lost my work” suggests that I did lose it.

Mixed conditionals: connect two times

Use a mixed conditional when the condition and result belong to different times.

Past condition → present result

Form: if + past perfect, would + base verb

• If I had studied design, I would have a different career now.
• If we had not missed the last bus, we would be home now.

The past cannot change, and it affects the present.

Present condition → past result

Form: if + past simple, would have + past participle

• If he were more organised, he would not have missed yesterday’s deadline.
• If this issue were unimportant, I would not have called you during your holiday.

The speaker describes a continuing quality or situation and imagines how it affected a past event.

Unless, as long as, provided that and in case

Conditional meaning is wider than if.

Linker	Meaning	Example
unless	if not	We will be outside unless it rains.
as long as	only if this condition is met	You can record the lesson as long as everyone agrees.
provided/providing that	on the condition that	We can extend the deadline provided that you email today.
even if	the result will not change	I will attend even if I have to join online.
in case	a precaution before a possible event	Take a copy in case the file does not open.

Do not treat in case as a direct replacement for if. “Take an umbrella in case it rains” means take it now as a precaution. “Take an umbrella if it rains” means wait for the rain, then take it.

Avoid a double negative with unless. Write “You cannot enter unless you have a pass,” not “unless you do not have a pass.”

Word order and punctuation

Both clause orders are correct:

• If you need a receipt, I will print one.
• I will print a receipt if you need one.

Use a comma when the if-clause comes first. A comma is not normally needed when the result clause comes first.

Six common mistakes to fix

Incorrect	Better sentence	Why
If it will rain, we will cancel.	If it rains, we will cancel.	Use present simple in a normal first-conditional if-clause.
If I would know, I would tell you.	If I knew, I would tell you.	The second conditional uses past simple after if.
If she studied, she would have passed.	If she had studied, she would have passed.	A third-conditional past condition needs past perfect.
If I had left early, I would catch the train.	If I had left early, I would have caught the train.	Both events are in the finished past.
Unless you do not hurry, you will be late.	Unless you hurry, you will be late.	Unless already contains the negative idea.
If I would be you, I would wait.	If I were you, I would wait.	Use the fixed hypothetical form if I were you.

Practice quiz

Use meaning before form. Identify whether each condition is general, realistically possible, imaginary now, imaginary in the past or connected across two times.

Which conditional fits?

Question 1 of 10

If you heat ice, it ___.

A.will meltB.would meltC.meltsD.would have melted

Printable worksheet

Answer the questions without looking at the chart. Use Print lesson near the top for a classroom handout; the answer key and reasons appear in the print version.

1. If you heat ice, it ___.
   A. will melt · B. would melt · C. melts · D. would have melted
2. If the client approves the design tomorrow, we ___ work on Monday.
   A. start · B. will start · C. would start · D. would have started
3. If I ___ more free time, I would join the evening class.
   A. have · B. will have · C. had · D. had had
4. If we had checked the address, we ___ lost.
   A. would not get · B. will not get · C. would not have got · D. did not get
5. If she had accepted that job in Rome, she ___ there now.
   A. would live · B. will live · C. would have lived yesterday · D. lives
6. Which first conditional sentence is correct?
   A. If it will rain, we will cancel. · B. If it rains, we will cancel. · C. If it rained, we will cancel. · D. If it would rain, we cancel.
7. You can borrow my laptop ___ you return it before five.
   A. unless · B. as long as · C. in case · D. even if not
8. Take a charger ___ the battery runs low.
   A. unless · B. provided that · C. in case · D. if only
9. Which sentence gives natural advice?
   A. If I am you, I will apologise. · B. If I were you, I would apologise. · C. If I had been you, I apologise. · D. If I would be you, I apologised.
10. Unless you save the file means ...
    A. if you save the file · B. because you save the file · C. if you do not save the file · D. after you saved the file

Show answers and explanations

1. melts — This is a general result, so the zero conditional uses present simple in both clauses.
2. will start — This is a real future possibility: if + present simple, then will + base verb.
3. had — The speaker imagines an unlikely or unreal present situation, so use the second conditional.
4. would not have got — The imagined condition and result are both in the past: had checked, would not have got.
5. would live — This mixed conditional links an unreal past choice to a present result: had accepted, would live.
6. If it rains, we will cancel. — Use present simple in the if-clause for this future condition, not will.
7. as long as — As long as introduces a necessary condition: returning it before five.
8. in case — In case explains a precaution taken before a possible problem.
9. If I were you, I would apologise. — If I were you, I would ... is the standard second-conditional pattern for advice.
10. if you do not save the file — Unless normally means if not. Avoid adding another negative after unless.

A 20-minute classroom activity

Goal: learners choose a conditional from meaning and defend the timeline.

1. Timeline sort, 5 minutes. Give pairs five situation cards: a general rule, tomorrow’s plan, an unlikely dream, yesterday’s mistake and a past choice affecting now. Learners match each to zero, first, second, third or mixed.
2. Build, 6 minutes. Each pair writes one complete sentence for three cards. They underline the condition once and the result twice.
3. Challenge, 5 minutes. Pairs swap sentences and change one timeline. For example, change a real future first conditional into a remote second conditional, then explain the difference in meaning.
4. Exit check, 4 minutes. Learners complete “If I had started learning English earlier, …” with either a past or present result. Their chosen result shows whether third or mixed conditional fits.

Mark the time relationship before correcting verb forms. A learner who understands the timeline can repair the structure; a learner who only memorises formulas often cannot explain the choice.

Key takeaways

• Zero describes a regular result; first presents a real future possibility.
• Second imagines an unreal or remote present/future; third imagines a different past.
• Mixed conditionals connect a condition and result in different times.
• In a normal first conditional, use present simple after if, then will in the result.
• Choose the meaning and timeline first, then check the verb pattern.

Review the verb forms in the 12 English tenses chart, especially past perfect for third conditionals. Use the irregular verbs reference when a past participle is uncertain, or practise tense choice with present perfect vs past simple.

Grammar references

The lesson, examples and exercises are original. For further reference, compare British Council: zero, first and second conditionals and British Council: third and mixed conditionals.