3. We use Conditional clauses 0 case to indicate permanent actions, physical laws or general truths.
The action is certain.
Tenses: Main clause = Simple Present. Conditional clause = Simple Present.
Gravity law: If you drop something, it goes down. Something goes down if you drop it.
Economic law: If there is a shortage of a product, its price goes up. (Law of offer and demand)
Physical law: If you heat water at 100°C, it boils.
General truths: If it rains, you get wet.
If public transport is efficient, people stop using their cars.
Permanent actions: If somebody has a cold next to me, I usually catch it.
If you mix red and blue, you get purple.
If you insult me, you get punched. (If = whenever)
Giving Instructions: If Bill phones, tell him to come home.
Ask your teacher if you don’t understand a subject.
5. We use 1st case conditional sentences to indicate possible conditions and their probable results.
The action is probable.
Tenses: If clause = Simple Present. Main clause = Simple Future (will)
Probability: If it rains, I’ll stay at home tomorrow.
Warnings: If I see a burglar trying to break into my car, I’ll call the police.
If you don’t study, you’ll fail your exams.
Using Modal verbs: You can learn anything if you really want.
I may go to a gym club if I have time.
Using Continuous tenses: If it’s raining so hard, why don’t you carry an umbrela?
I’ll be having dinner with my friend if he/she invites me.
Using Present Perfect: If we have finished our meals, let’s pay. (At a restaurant)
If you have finished your tests, hand them in. (At school)
7. We use 2nd case conditional sentences to indicate present unlikely or hypothetical conditions and
their probable results.
The action is unreal.
Tenses: If clause = Simple Past (Subjunctive). Main clause = Simple Conditional (Would)
Hypothetical Condition: If I had a lot of money, I’d buy a 2019 Vision EQS Mercedes Benz.
If people didn’t have to quarantine, they’d go out with their friends.
Use of were (for all the people): If I were /was not kept in quarantine, I’d travel to Europe.
Using continuous tenses: If it wasn’t/weren’t raining cats and dogs, I’d be jogging in the park.
Advice: If I were you, I’d give up smoking.
If I had your fever and headache, I’d definitely go to a hospital.
Using a modal: I’d help you with your exercises if I could/were able to.
9. We use the 3rd case conditional sentences to indicate truly hypothetical or unreal past actions because
it is now too late for the condition or its result to exist.
Tenses: If clause = Past Perfect. Main clause : Conditional perfect / modal + perfect infinitive (would
have done)
Past hypothesis: If Tom had studied, he would have passed his exams. Tom would’ve passed his exams if he ‘d
studied.
(So, Tom didn´t passed his exams because he didn´t studied).
You can add some connotation using a modal:
If Tom had studied, he could have passed his test. (Past inability)
If Tom had studied, he might have passed his test. (Past improbability)
If you had had a high temperature and sore throat, you should have called your health insurance doctor. (Past
advice/suggestion).
Your friend hadn´t borrowed some money from you if you hadn´t told him that you won the lottery.
We can emphasize these sentences using inversion constructions. We omit if.
Had I known you were coming home, I would have made a delicious chocolate cake.
11. We use 4th case conditional sentences to unreal past conditions and their probable results in the
present.
Tenses: If clause = Past Perfect. Main clause = Simple Conditional (Would).
If I had looked at the GPS map before starting to drive, I woudn’t be lost now.
(I haven’t looked at the GPS map before starting to drive so I’m lost now).
I would be able to buy that car if I had saved a lot of money.
The Company would have sacked Tom months ago if They didn’t trust him.
USING UNLESS
Unless means the same as if...not. Like if, it is followed by a present tense, a past tense or a past perfect (never by
'would'). It is used instead of if + not in conditional sentences of all types:
Type 1: Unless + present:
You´ll be sick unless you quarantine. (You’ll be sick if you don’t quarantine).
Type 2: Unless + past:
She would be here by now unless she was stuck in the traffic.
12. Type 3: Unless + Past Perfect.
Tom wouldn´t have failed his exams unless he had studied.
We can for conditionals by using words, expressions such as unless, providing, provided that, so/as long as, on
condition (that), what if, suppose, supposing, otherwise (= if not), but for, even if, or else, in the event of.
I agree to work on Saturdays on condition (that)/providing I´m paid overtime.
Note: We can use will, would and should after if to make a polite request or express insistence or uncertainty. In
this case if means whether.
I wonder if/whether you’ll call me tomorrow.
Should you need further information, let me know.
If you will wait a minute, the manager will be able to see you.
I would be very grateful if you would send me all the details by email.
Whether:
• used when talking about a choice you have to make or about something that is not certain:
Maurice asked me whether I needed any help.
• used to say that something definitely will or will not happen whatever the situation is:
Look, Kate, I'm calling the doctor, whether you like it or not.
Poor farmers, whether owners or tenants, will be worst affected.
