Conditionals Part 2

This article follows the introduction in  Conditionals. Instead of the terms "condition" and "result", here we will talk about am if-clause and a result clause. For example in "If it rains tomorrow, we'll stay at home.", "If it rains tomorrow" is the if-clause and "we'll stay at home" is the result clause.

Here we look at conditional sentences by splitting them into two main categories:
REAL (the action takes place when the condition is present) and UNREAL (the action cannot take place because the condition is not present).

REAL CONDITIONAL SENTENCES

They have this name because the result can realistically occur, as long as the condition is in place. We observe the following two cases:
1) The condition and result take place at the same time. This is the so called ZERO type (as long as the condition is present, the result is always present).
In these sentences IF is almost identical to WHEN.

The time can be both present and past:
а) present

If-clause	Result clause
present tense or past simple tense	resp. present or past simple tense modal verb and infinitive imperative

If I spend more than ten minutes in the sun, I get a sunburn. (present simple + present simple
If I'm driving, I always wear my driving glasses. (present continuous + present simple)
If I've eaten too much for lunch, I tend to feel sleepy in the afternoon. (present perfect + present simple)
When I was young, if we needed advice, we asked our parents. (past simple + past simple)
If you want to travel to South America, you must get some vaccinations. (present tense + modal verb)
If you have a toothache, go to the dentist! (present tense + imperative)
b) past

If-clause	Result clause
past tense	past tense used to would + infinitive (about repetitive past actions)

If he had time, he always came to see me.
If he wasn't working at the weekend, he went home to get some sleep. (past continuous + past simple)
If I was thirsty, I used to drink ice cold water. Now I know I shouldn't. (past simple + used to)
My grandma was a great cook. If she made breakfast, we'd all get up and go to the kitchen really fast. (past simple + would)

2) The result takes place after the condition appears.
This is the so called FIRST type, or in other words when a certain condition is fulfilled, the result will appear.

If-clause	result clause
present tense	modal verb (will, may, might, can, should) and infinitive imperative be going to

Examples:
If we don't leave soon, we will miss the train. (present simple, refers to future time + will)
If you are hungry, you'll find some sandwiches in the fridge. (present simple, refers to present time + will)
If you are looking for Molly, you'll find her upstairs in her room. (present continuous for a present action + will)
If you are staying for the weekend, we'll go to the cinema. (present continuous for future arrangement + will)
If I've finished writing my paper by tonight, I'll go out with my friends. (present perfect, which emphasizes that one action depends on the completion of another + will)
If you've done the dishes, please mop the floor. (present perfect + imperative)
If you ask George, he may/might be able to help you. (present simple + may/might to express possibility)
You can/may leave the room if you've finished the test. (present perfect + can/may for permission)
If he doesn't come soon, we must / will have to leave without him. (present simple + must/will for obligation)
If you ever go to Chicago, you should take a boat trip on the river. (present simple + should for suggestion)
If you don't watch your step, you are going to fall over. (present simple + be going to for prediction)

UNREAL CONDITIONAL SENTENCES

In case of these the action cannot take place because the condition is absent.
Depending on whether the condition and/or the result refer to the present or future, there are 4 types:

1) The condition is not currently present, and therefore the result is also unreal (SECOND conditional):

If-clause	Result clause
simple past tense	would/another modal verb + simple/continuous infinitive

If he had time, he would come to see me. (past simple + would with simple infinitive)
If I lived by the sea, I would be lying on the beach right now. (past simple + would with continuous infinitive)
If no one was late, we could start the meeting on time. (past simple + could)
If you asked George, he might be able to help you. (past simple + might)

In the result clause you can also use:
- could:
I'd go to the beach with you if I could swim. (ability)
If you could be a famous person, who would you be? (possibility)
I wouldn't go to bars if people could smoke inside. (permission)
- were to
If he were to propose to you now, what would you say?
- would (to express requests), and sometimes the result clause is omitted:
If you'd just fill in this form, please.

*We often say "If I were you ,...". Why "were"?
What I called "past simple" above is actually the "past subjunctive", where the correct form of be is were (including "If he were my brother", "If I were there"). Was is slowly becoming the norm, but in "If I were you ,...", were is more persistent and is used in all cases.

2) The condition was not present in the past, so the result never took place (THIRD conditional):

If-clause	Result clause
past perfect tense	would or another modal verb with a perfect infinitive (have done)

If he had been in the area yesterday, he would have come to see me.
If the driver had fastened his seat belt, he would probably have survived the accident. (past perfect + would with perfect infinitive)
If the driver had been wearing a seat belt, he would probably have survived the accident. (past perfect continuous + would with perfect infinitive)
If I had had the right tools, I could have fixed my bike.
If the weather had been worse, they might not have reached the top.

In the result clause we can also use:
- could:
If he could have got to the station on time, he might have caught the train. (ability)
If I could have known this would happen, I'd never have started dating him. (possibility)
- were to:
If he were to have asked me, I would have said yes.

3) The condition is not present in general, and that is why the result did not take place in the past (mixed conditionals)

4) An absent past condition means lack of result in the present (mixed conditionals)

Examples of the last two times you can find in the short article Conditionals.