If you are in Year 2 of high school, this year’s English programme brings in the second conditional in November. This applies to the science high school (liceo scientifico), the human sciences high school, the language high school and technical schools alike: the programme of the first two years is almost identical everywhere, only the weekly hours change. The third conditional comes later, usually between January and February, but the test that examines the choice among all four conditionals together often falls in December: you have eight to ten weeks to fix the pattern properly, not to learn it the night before.
When to use which conditional
The problem is not so much the form (once you have learned the table you just apply it) as understanding which of the four a given sentence needs. The key is probability: how real or unreal the condition you are talking about is.
| Conditional | If-clause | Main clause | Use |
|---|---|---|---|
| Zero | if + present simple | present simple | things that are always true, general laws |
| First | if + present simple | will + infinitive | real condition, possible future |
| Second | if + past simple | would + infinitive | unreal condition in the present/future, hypothetical |
| Third | if + past perfect | would have + past participle | impossible condition in the past, it did not happen |
One example for each, with the Italian translation, which helps you feel the difference:
- Zero: If you heat water to 100°C, it boils. (Se scaldi l’acqua a 100°C, bolle.) Always true, nothing hypothetical.
- First: If it rains tomorrow, I will stay home. (Se domani piove, resto a casa.) Real condition: it might really rain.
- Second: If I won the lottery, I would travel the world. (Se vincessi alla lotteria, viaggerei per il mondo.) Hypothetical condition: I have not won, I am only imagining.
- Third: If I had studied more, I would have passed the exam. (Se avessi studiato di più, avrei passato l’esame.) Impossible condition: the exam has already happened, I can no longer change what I did.
“If I were”: the special case of the second conditional
In the second conditional, with the verb to be, the correct form for all persons (including I and he/she/it) is were, not was:
- If I were you, I would ask for help. (Se fossi in te, chiederei aiuto.)
- If she were taller, she could reach the shelf.
Was in this context (if I was you) is heard in informal speech, but in writing, and in what the test asks for, were stays for all persons. It is one of the few forms in English where the subjunctive survives as a form distinct from the indicative, and it is worth learning as it is, without looking for any further logic.
Unless: the other side of if… not
Unless means “unless” (a meno che) and is equivalent to if… not, but be careful: after unless you do NOT repeat the negation.
- Unless you study, you will fail. = If you don’t study, you will fail. (A meno che tu non studi, fallirai.)
- Wrong: Unless you don’t study… This is an incorrect double negative, and it is the most common mistake when translating from the Italian a meno che tu non.
Unless is used mostly in the first conditional (real condition), more rarely in the second.
Typical mistakes of Italian speakers
1. Putting would in the if-clause
Wrong: If I would have more time, I would help you. Correct: If I had more time, I would help you.
This is by far the most frequent mistake. In Italian we say se avrei più tempo (“if I would have more time”) only in incorrect speech, but the temptation in English is stronger because would seems “natural” to put wherever there is a hypothesis. Fixed rule: would (or would have) goes always and only in the main clause, never in the if-clause.
2. Translating the Italian subjunctive word for word
Italian has the imperfect subjunctive (se studiassi) and the past perfect subjunctive (se avessi studiato), and whoever translates mechanically risks complicating the English structure, which is in fact simpler: past simple for the second, past perfect for the third, full stop. There is no need to look for an “English subjunctive” because it does not exist as a separate verb form: the function is already inside if + past simple/past perfect.
3. Confusing the third conditional with an isolated past perfect
Wrong: If I had more money, I would have bought that car. (it mixes second and third) Correct: If I had had more money, I would have bought that car. (full third conditional: the past perfect of the verb have is had had, when the condition concerns the past)
The third conditional requires the past perfect in the if-clause (which with have becomes had had) and would have + past participle in the main clause. A common mistake is to leave just a past simple in the if-clause, which turns it into a second conditional (a present hypothesis) when the whole sentence is in fact about the past.
Mixed conditionals: just a mention
Sometimes a condition in the past has a consequence in the present, and then the third and the second are mixed:
If I had studied medicine, I would be a doctor now. (Se avessi studiato medicina, a condition in the past that did not happen, adesso sarei un medico, a consequence in the present.) The if-clause is in the past perfect (as in the third), the main clause has would + bare infinitive (as in the second), because the result concerns now, not a moment in the past. For Year 2 level it is enough to recognise it when you meet it in a text; building it actively is a later step.
Test what you have learned
Before the written exercises, if you want to check at a glance whether you have understood the pattern, you can try the section dedicated to languages on the school practice tests page: today there is not yet a practice test dedicated to conditionals, but you will find the ones already available for maths and physics, useful to get you used to the timed-test format.
Three worked exercises
Exercise 1: complete with the right conditional:
a) If it ___ (rain) tomorrow, we ___ (cancel) the trip. b) If I ___ (be) you, I ___ (not / say) that. c) If she ___ (study) harder last year, she ___ (pass) the exam. d) Water ___ (freeze) if the temperature ___ (drop) below 0°C.
Solutions: a) rains / will cancel: first conditional, real condition in the future. b) were / wouldn’t say: second conditional, unreal hypothesis in the present, were for all persons. c) had studied / would have passed: third conditional, impossible condition in the past (“last year” signals it). d) freezes / drops: zero conditional, scientific law that is always true, present simple in both parts.
Exercise 2: key word transformation (B1 style: rewrite the second sentence so that it means the same as the first, using the given word):
a) I don’t have a car, so I can’t drive you home. (WOULD) → If I had a car, I would drive you home.
b) She forgot her umbrella, so she got wet. (HADN’T) → If she hadn’t forgotten her umbrella, she wouldn’t have got wet.
c) You don’t study, so you fail every test. (UNLESS) → Unless you study, you will fail every test.
The mistake to avoid in (b) is forgetting that both actions are in the past: both the cause (she did not take the umbrella) and the consequence (she got wet) have already happened, so you need the full third conditional, with would have + participle.
Exercise 3: translate from Italian:
a) “Se fossi in te, chiederei scusa.” (“If I were you, I would apologise.”) → If I were you, I would apologize.
b) “Se avessi saputo, ti avrei chiamato.” (“If I had known, I would have called you.”) → If I had known, I would have called you.
c) “Se piove, restiamo a casa.” (“If it rains, we stay at home.”) (general rule, not a specific case) → If it rains, we stay home. (zero conditional: the translation with will would be acceptable only if you are talking about a specific decision for an upcoming occasion, not a habit.)
Frequently asked questions
Why do you sometimes hear if I was instead of if I were? It is a form that is common in informal speech and in some varieties of American English, but in writing, and in all school tests and Cambridge exams, the correct form remains were for all persons in the second conditional.
Is the third conditional connected to the present perfect or the past simple that I study in other units? The past perfect of the third conditional (had studied) is a tense apart from the ones you have probably already worked on in choosing between the past simple and the present perfect: I talk about that in past simple or present perfect: the typical mistakes of Italian speakers, which is also useful so as not to confuse the forms when they appear in the same sentence as a conditional.
Are there English words that mislead you on this topic too? Not specifically in conditionals, but if the mistake of translating literally from Italian happens to you often, it is worth taking a look at false friends: 15 English words that do not mean what you think: same logic, that is, trust automatic translation less and the structure English really uses more.
If I take a certificate exam in Year 4, do conditionals come back? Yes, they are one of the central grammar topics of Use of English at B2 First: I talk about it in B2 First: how to pass Use of English, with a study plan designed for it.
You will find the general picture of grammar and languages on the English and languages page, and if before the test you want to review the four conditionals with examples taken from your real mistakes you can start with a free introductory call.
