This document discusses the four basic types of conditional sentences in English: zero, one, two, and three. It explains that each type has an if clause and a main clause. The zero conditional describes always true situations and uses the simple present tense in both clauses. Type one refers to present or future possibilities and uses the simple present and future tenses. Type two also refers to present/future but are less likely possibilities, using the simple past and future-in-the-past tenses. Type three always refers to the past, using the past perfect in the if clause and conditional perfect in the main clause to discuss unlikely past situations.

1. English GrammarEnglish Grammar
If Clauses & ConditionalIf Clauses & Conditional
SentencesSentences

2. There are four basic types of conditionalThere are four basic types of conditional
sentences in the English language. Eachsentences in the English language. Each
type has two parts – the main clause andtype has two parts – the main clause and
the if clause.the if clause.
If ClauseIf Clause
An if clause begins with ‘if’. It cannot standAn if clause begins with ‘if’. It cannot stand
independently. It gives an incompleteindependently. It gives an incomplete
meaning. eg: If you work hard,meaning. eg: If you work hard,
Main ClauseMain Clause
It can stand independently and it gives aIt can stand independently and it gives a
complete meaning. eg: You will pass thecomplete meaning. eg: You will pass the
exam.exam.

3. Four Types of ‘If Clause’Four Types of ‘If Clause’
Type Zero: Iype Zero: I taketake my umbrella if itmy umbrella if it rainsrains..
Type One: IType One: I'll call'll call you if Iyou if I workwork late.late.
Type Two: If the busType Two: If the bus didn't arrivedidn't arrive on time, Ion time, I
would drivewould drive you to the airport.you to the airport.
Type Three: SheType Three: She wouldn't have comewouldn't have come if Iif I
hadn't invitedhadn't invited her.her.

5. Zero conditionalZero conditional
The zero conditional describes situationsThe zero conditional describes situations
that are always true. If has the same meaningthat are always true. If has the same meaning
as when or whenever.as when or whenever.
If I go to school, I get up at seven.If I go to school, I get up at seven.
If you park your car on double yellow lines,If you park your car on double yellow lines,
you pay a fine.you pay a fine.
We use the Simple Present Tense in both theWe use the Simple Present Tense in both the
main clause and the if clause.main clause and the if clause.

6. If Clause Main Clause
If + Simple Present Simple Present
If you heat the water
to 100 degrees, it boils.

7. Type OneType One
Type one refers to the present or future. It isType one refers to the present or future. It is
used to speculate about possible situationsused to speculate about possible situations
that canthat can really happen.really happen.
If he studies hard, he'll pass the exams.If he studies hard, he'll pass the exams.
If we catch the 10.15 train, we will arrive onIf we catch the 10.15 train, we will arrive on
time.time.
We use the Simple Present Tense in the ifWe use the Simple Present Tense in the if
clause and Simple Future in the main clause.clause and Simple Future in the main clause.

8. If Clause Main Clause
If + Simple Present Simple Future
If I find her
address,
I will send her an
invitation.

9. Type TwoType Two
Type two also refers to the present or future. In typeType two also refers to the present or future. In type
two conditional sentences we speculate abouttwo conditional sentences we speculate about
situations that will probablysituations that will probably never happen.never happen.
If I had more time, I would help you. (But I am notIf I had more time, I would help you. (But I am not
free at the moment. I can't help you).free at the moment. I can't help you).
If I won a million dollars, I would start a businessIf I won a million dollars, I would start a business
of my own. (But I know that it is not realistic.)of my own. (But I know that it is not realistic.)
We use the Simple Past Tense in the if clause andWe use the Simple Past Tense in the if clause and
Future in Past in the main clause.Future in Past in the main clause.

10. If Clause Main Clause
If + Simple Past Future in Past
If I found her
address,
I would send her an
invitation.

11. Future in PastFuture in Past
Would + Base form of the verbWould + Base form of the verb
Should + Base form of the verbShould + Base form of the verb
Could + Base form of the verbCould + Base form of the verb
Might + Base form of the verbMight + Base form of the verb

12. Type ThreeType Three
The type three conditional sentences always referThe type three conditional sentences always refer
to the past. We speculate about situations that didto the past. We speculate about situations that did
not happen in the past.not happen in the past.
If I had won a million, I would have started aIf I had won a million, I would have started a
business of my own. (But I didn't win anything.)business of my own. (But I didn't win anything.)
If he had met her, he would have told her.If he had met her, he would have told her.
(Unfortunately, he didn't meet her.)(Unfortunately, he didn't meet her.)
If we hadn't practised, we wouldn't have wonIf we hadn't practised, we wouldn't have won
the match. (But we practised and won.)the match. (But we practised and won.)
We use the Past Perfect in the if clause and wouldWe use the Past Perfect in the if clause and would
+ have + Past Participle(V3) in the main clause.+ have + Past Participle(V3) in the main clause.

13. If Clause Main Clause
If + Past Perfect would/could/might +
have + Past Participle
If I had studied
harder,
I would have passed the
exam.

14. Special NoteSpecial Note
If the "if" clause comes first, a comma isIf the "if" clause comes first, a comma is
usually used. If the "if" clause comesusually used. If the "if" clause comes
second, there is no need for a comma.second, there is no need for a comma.
Water boils if you heat it to 100 degrees.Water boils if you heat it to 100 degrees.
You will pass the test if you study hard.You will pass the test if you study hard.
I would buy a big house if I had a millionI would buy a big house if I had a million
dollars.dollars.
I would have passed the exam if I hadI would have passed the exam if I had
studied harder.studied harder.

16. Thank You
Sojan Abraham,
for Team ELT,
9495426776