Conditional Sentences: Real and Unreal

We use conditional sentences a lot. Here are a few:

If you are late to the theater,
you will not be seated until intermission.
If you mix ammonia and chlorine bleach,
you will create a smelly, dangerous solution.
If you take the 8 a.m. flight to New York,
you don't have to change planes.


What are the differences in these three groups of conditional sentences?

Notice that the first group of three sentences are all true. Well, we don't know about the 8 a.m. flight, but it sounds as if the information is being given on good authority! All three sentences tell what will happen (result) if certain conditions are met. These are real conditions.

The second group tells what might happen (result) if some unreal conditions were met. I'm not the ambassador, I'm not taller, and I don't speak French. Thus, none of these outcomes (results) will materialize.

The third group just speculates about what would result if past conditions had been different. These are considered unreal past conditional sentences.
 

Forming Conditional Sentences

Conditional sentences have two clauses:
 

Dependent Clause  Independant Clause
"If" Clause  "Result" Clause
Condition  Result
If you stay in the sun too long,  you will get sunburned!
If you drink too much whiskey,  you will get sick.
If you study hard and practice a lot, your English will improve.
 
The clauses can be reversed. If the dependent (If) clause comes first in the sentence, you must separate them with a comma. You shouldn't use a comma if the independent clause comes first.
 
You will get sunburned if you stay in the sun too long!
You will get sick if you drink too much whiskey.
Your English will improve if you study hard and practice a lot.

The difference in meaning between between the first pattern and the second is in the statement's intent.
 

Specific Warning: If you stay up too late, you'll be really tired tomorrow.
General Statement:  You'll be really tired tomorrow if you stay up too late.
 

Verb Forms with Conditionals

Factual conditions:
 

If clause=present tense  Result clause=future tense
If you eat too much ice cream, you'll get sick.
If Betsy needs help,  she will call us.

Unreal Conditions--present:
 

If clause=simple past Result clause=would or could + base form of verb
If I had more time,  I'd do exercises everyday.
If you were* rich,  you could buy a large house in the suburbs.
If Patricia owned a dog,  she would walk him everyday.

Unreal Conditions--past:
 

If clause=past perfect Result clause=would have + past participle or   would + be
If Ronald had stayed in school, he would have gotten a better job.
If I had invented the personal computer, I would be rich today.
If the kids hadn't eaten all the ice cream,  we would have had dessert.

 
Questions with Conditions

You can, of course,  ask questions with conditions:

Yes-no Questions
Does Homer get angry if you forget to feed him?
Would it hurt the car if you put apple juice in the gas tank?
Does it hurt your computer if you leave it on all night?

Information Questions
What happens to your computer if you leave it on all night?
What would happen if you put apple juice in the gas tank?
Unreal: What would you do if you got the job? Real: What will you do if you get the job?

Remember: The main thing to consider when you are writing conditional sentences is whether or not the condition (IF clause) is real or possible.

Unreal condition:
If I were the king of the world, I would make it easy to write English.

Real condition:
If I'm your teacher next year, I'll give you some writing exercises.

Practice #1
Practice #2
Back to the Green Table of Contents
 

(c)David Tillyer

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