Conditional sentences

1. Concepts

In English, conditional sentences are used to express and explain an event that may happen when the condition mentioned occurs. Most conditional sentences contain “if”. A conditional sentence has two clauses.

• The main clause is also called the result clause.

• The clause containing “if” is a subordinate clause or conditional clause, it states the condition for the main clause to become true.

Usually the main clause will come before the following subordinate clause. However, we can move the subordinate clause to the front of the sentence and add a comma after the subordinate clause to separate the subordinate clause and main clause.

For example:

• If the weather is nice, I will go to Cat Ba tomorrow.

• If I were you, I would buy that laptop.

• I would have gotten better marks if I had learned hard.

2. Classification

Corresponding to the times when the condition occurs, conditional sentences are also classified into forms based on those timestamps. Let's learn in detail the structure and usage of each type of conditional sentence right below!

2.1. Conditional sentences type 0

Conditional sentences type 0 are used to explain situations that are considered true, usually facts in life, such as science.

Subordination	Main clause
If + S+ V (Simple tense)	S + V (Simple tense)

For example:

• If you freeze water, it becomes a solid.

• Plants die if they don’t get enough water.

• If public transport is efficient, people stop using their cars.

In addition, type 0 conditional sentences are also used to give instructions and suggestions.

For example:

• If Bill phones, tell him to meet me at the cinema.

• Ask Pete if you’re not sure what to do.

• If you want to come, call me before 5:00.

In a zero-type conditional sentence, we can replace “if” with “when” without changing the meaning of the statement:

• If you heat ice, it melts.

• Ice melts if you heat it.

• When you heat ice, it melts.

• Ice melts when you heat it.

2.2. Conditional sentences 1

Conditional sentences type 1 are used to describe events that are likely to happen in the present or future and their results.

Subordination	Main clause
If + S + V (Simple tense)	S + will + V (Future simple)

For example:

• If you don’t hurry, you will miss the bus.

• If I have time, I’ll finish that letter.

• What will you do if you miss the plane?

In conditional sentences type 1, instead of using the future tense, we can also use modal verbs to express a degree of certainty or suggest a certain result:

• If you drop that glass, it might break.

• I may finish that letter if I have time.

• If he calls you, you should go.

2.3. Conditional sentence type 2

Conditional sentences type 2 are used to express situations that are not real and cannot happen in the future and assume the result if it could happen.

Subordination	Main clause
If + S + V-ed (Simple past)	S + would + V (form 1 tense)

For example:

• If the weather wasn’t so bad, we could go to the park.(But the weather is bad so we can’t go.)
• If I was the Queen of England, I might give everyone a chicken. (But I am not the Queen.)
• I would be working in Italy if I spoke Italian. (But I don’t speak Italian, so I am not working in Italy)

2.4. Conditional sentence type 3

Conditional sentences type 3 are used to describe events that did not happen in the past and to determine the result if it had happened. This sentence structure often implies regret or blame.

Subordination	Main clause
If + S + had + V-PII (Past Perfect)	S + would + have + V-PII (2nd tense form)

For example:

• If I had worked harder I could have passed the exam. (But I didn’t work hard, and I didn’t pass the exam.

• If I had known you were coming I would have baked a cake. (But I didn’t know and I didn’t bake a cake.

• If she hadn’t got a job in London , she would have married him.

2.5. Mixed conditional sentences

Mixed conditionals express contrary events that happened in the past and assume the result if these things had actually happened. These results would be contrary to the current truth.

Subordination	Main clause
If + S + had + V-PII (Past Perfect)	S + would + V

For example:

• If I had studied I would have my driving license. (but I didn’t study and now I don’t have my license)
• I could be a millionaire now if I had taken that job. (but I didn’t take the job and I’m not a millionaire)
• If you had spent all your money, you wouldn’t buy this jacket. (but you didn’t spend all your money and now you can buy this jacket)

3. Note

Just like verbs with regular verbs and irregular verbs, conditional sentence structures also have special cases that need attention.

3.1. Conditional sentences have negative clauses

In the conditional sentence there issubordinate clause in negative form, We can use “unless” instead of “if not…”

For example:

• I will buy you a new laptop if you don’t let me down.

        => I will buy you a laptop  unless you let me down.

• I will go to Cao Bang tomorrow if it doesn’t rain.

=> I will go to Cao Bang tomorrow unless it rains.

• Mary can’t let you in if you don’t give her the password.

=> Mary can’t let you in unless you give her the password.

3.2. Conditional sentences 1

In type I conditional sentences, we can use the simple future tense in the subordinate clause if the subordinate clause takes place after the present clause takes place.

For example:

• If aspirin will ease my headache, I will take a couple tonight.
• If you will take me to the park at 9 a.m, I will wake you up at 8 a.m.
• If I will have English lesson this afternoon, I will book a grab to school now.

3.3. Conditional sentence type 2

In conditional sentences type 2, we  use “were” instead of “was”

For example:

• If I were you, I would never do that to her.
• If I were you, I would take part in this competition.
• If I were you, I would believe in her.

This usage is more formal and common.

3.4. Conditional sentences type 2 and conditional sentences type 3

The usage of conditional sentences type 2 and conditional sentences type 3 are often used in sentence structure wish andstructure of sentences would rather to express regret or blame someone for doing or not doing something:

For example:

• If I had reviewed for the exam, I would not have got mark D!

=> I wish I had reviewed for the exam.

=> I would rather I had reviewed for the exam.

• If I had gone to that party, I could have met her.

=> I wish I had gone to that party.

=> I would rather I had gone to that party.