1. CONDITIONAL SENTENCES
Conditional sentences consist of two clauses – a main (‘conditional’) clause containing a verb in a form with will or would, and a subordinate clause that is introduced by if.
Examples:
Joan will help you if you ask her.
If I were you, I’d buy a cheaper car.
order of clauses can be changed.
Whenever we begin with the subordinate clause, we normally use a comma (as in 2nd example)

2. Cond. Cont’d. I’ll turn on the heating if it gets dark.
If it gets dark, I’ll turn on the heating.
If is barely pronounced in casual conversation. The vowel /i/ disappears entirely, and even /f/ is whispered. A phrase like If I were you is pronounced /faiwәju:/.
There are 4 types of conditionals:

3. 1. Zero conditional sentences
Form:
If clause
Conditional clause
If + present tense
Present tense
If I eat late at night,
I normally have trouble sleeping.
Conditional clause
If clause
Present tense
If + present tense
Most cats purr
If you tickle them under the chin

4. Use of zero conditional
To express general truths.
e.g. If you boil water, it evaporates.
Habits
e.g. If I drink coffee, I get headaches.

5. 2. Type 1 (first or future conditional)
If clause
Conditional clause
If + present tense
Future tense
If you help me with my essay,
I’ll tidy up your room.
Conditional clause
If clause
Future tense
If + present tense
He’ll get here early
If he catches the fast train.

6. first type – basic usage
Persuasion:
e.g. I’ll take the children to the party if you collect them from school.
Warning:
e.g. If you try to take a short cut, you’ll get lost.
Threat:
e.g. If you poke your sister again, I’ll thrash you.

7. First type other forms
If + present, imperative (to give advice and instructions)
e.g. If you go to Hagkaup, bring back a carton of cream please.
Present continuous: We’re staying at home on Tuesday if the transport strike goes ahead.
Going to: We’re going to build a house if the bank gives us a loan.
Present perfect: If it hasn’t rained by the weekend, we’ll have to water the garden
Present continuous: If they’re watching TV, they won’t hear you.

8. 3. Type 2 (2nd, ‘hypothetical or unreal conditional)
Used to refer to or speculate about sth. that is impossible or ‘contrary to fact’ (unreal present condition)
Type 2 conditional sentences can refer to the present or the future.

9. Type 2 – basic form Time reference If clause Conditional clause
Present:
If he didn’t annoy me so much,
I’d spend more time in his office.
Future:
If I got an invitation,
I’d go there right away.

10. Type 1 vs type 2
Both type 1 and 2 conditionals can refer to the future. Compare:
type 1: If it gets colder tonight, I’ll turn on the heating. (a real possibility)
type 2: If it got colder tonight, I’d turn on the heating. (not a real possibility)

11. Type 2 – notes
In the if clause use were in place of was. (N.B. was can be heard in spoken English)
e.g. I’d be able to find the information if I were at home.
Use the idiom if I were you to express advice.
e.g. If I were you, I’d see a doctor.

12. Type 2 – other forms Should is often used after I and we.
e.g. I shouldn’t get to sleep at all if I lived next to that noise.
Should in official/commercial correspondence.
e.g. I should be grateful for an early response to my letter.

13. Type 2 – other forms cont’d.
Were + infinitive (makes the even more hypothetical or the statement more tentative, therefore, more polite)
e.g. If the river were to rise above the height of the flood barrier, there would be absolutely nothing we could do to save the city.
Were + subject : Were you to accept my offer, I’d personally oversee arrangements

14. Type 2 – other forms cont’d.
If + would (In US English, would is often used in the if clause.)
e.g. I’d eat something if I wouldn’t have indigestion.

15. 4. Type 3 (third or past conditional)
If clause
Conditional clause
If + past perfect
would + have + past participle
If we had hurried,
we wouldn’t have missed the train.

16. Type 3 cont´d. Conditional clause If clause
Would + have + past participle
If + past perfect
I would have (would’ve) been more sympathetic,
if she hadn’t accused me of lying.

17. Type 3 - usage
Used to speculate about past events, and about how things that happened or didn’t happen might have affected other things
Often used to express reproach and regret.
e.g. If you hadn’t driven so fast, you would never have had the accident.
I wouldn’t have left my job if I’d known how difficult it is to find another one.

18. Type 3 – usage cont’d.
Type 3 conditional is also used to make excuses.
e.g. If I hadn’t been held up by the traffic jam, I would’ve been here on time for the meeting.

19. Type 3 – other forms If clause Conditional clause
Many native speakers use a non-standard variant of the Type 3 conditional.
If clause
Conditional clause
If + had have + past participle
Would + have + past participle
If they’d have arrived on time.
I’d have let them into the cinema.

20. conjunctions
Other conjunctions are used instead of if. These include: supposing, as long as (Type 1&2); provided, on condition (that), unless (all types)
e.g. Where will you go supposing you have a holiday?
I would help him as long as he asked me nicely.
I wouldn’t have come round unless you’d phoned and asked me to.

21. Modal verbs in conditional sentences
Zero conditionals
We can use a modal verb in either or both clauses of a zero conditional
e.g.
If you have a ticket , you can go through now.
You should wear glasses if you can’t see.

22. Modal verbs cont’d.
Type 1. We can use may, might and could to show that something is a possible consequence (rather than a certain one)
e.g.
I can bring something to eat if you want.
If you listen to me carefully, you may learn something useful.

23. Modal verbs cont’d. Type 2 and 3
might and could in place of would in Type 2&3.
e.g.
If you explained more clearly, I might understand.
If we hadn’t worked so hard, we could’ve missed our deadline.

24. Will and would in if clauses
would (like) may appear in the if clause where the meaning is similar to want.
e.g.
If you would like to sit down, please help yourself to a seat.
Will can be used in the if clause where the meaning is similar to be perpared to/be willing to
If you’ll wait a minute, the doctor will be here to see you.

25. Will and would in if clauses cont’d.
Will and would can suggest perverse (siðspilltur) and deliberate behaviour (normally stressed)
e.g.
If you will argue with everyone, you can’t expect to be popular.
If you wouldn’t take so much time off, you might earn more.

26. Mixed conditionals
Things we did in the past may have present consequences, and equally these past events may be the result of present facts. Look at this situation:
Past action:
You wasted money last week.
Present consequence:
We can’t afford a good holiday.

27. Mixed conditionals cont’d.
If clause (Type 3)
Main clause (Type 2)
If you hadn’t wasted so much money last week,
We’d be able to afford a better holiday.

28. Mixed conditionals cont’d.
Present (general) fact:
I am very busy.
Past consequence:
I wasn’t able to take off any time last week.
If clause (Type 2)
Main Clause (Type 3)
If I weren’t busy.
I could’ve taken off a few days last week.