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What are If and Whether? English knowledge about the If and Whether structures

Have you ever wondered about whether something is true or false? In English, the structures commonly used to express this are If and Whether. In today's article, let's explore in detail the knowledge about the If and Whether structures, including formulas, examples, and exercises with answers!

I. What is If?
II. What is Whether?
III. How to Use the Structures If and Whether
1. 1. Indirect Questions with If and Whether
2. 2. If and Whether with or not
IV. Distinguishing Between If and Whether
VI. Common Mistakes When Using If and Whether
VII. Exercises on the Structures If and Whether with Answers
1. 1. Exercises
2. 2. Answer keys

I. What is If?

If (pronounced /ɪf/) functions as both a conjunction and a noun:

As a conjunction, If means: "if," "in case of," or "although." For example:
- I'll pay you double if you get the work finished by Friday.
- They're great kids, even if they can be demanding.
As a noun, If means: something that is uncertain or undecided. For example: There's a big if hanging over the project.

Common idioms with If:

Common idioms with If	Meaning	Example
If and when	Used to emphasize uncertainty about a future event, indicating that it may or may not happen	If and when you decide to come visit, let me know so I can prepare a room for you.
If anything	Used to suggest that the opposite of what has been previously stated may be true or more relevant	He's not lazy; if anything, he works too hard.
If I were you	Used to give advice or suggestions, indicating what the speaker would do in the listener's situation	If I were you, I would start studying for the exam now instead of waiting until the last minute.
If need be	Used to imply that something will be done if necessary	We can postpone the meeting if need be, but I would prefer to keep it as scheduled.
If you will	Used to indicate that the speaker is giving permission or acknowledging someone else's wish or preference	He’s the Mozart of our generation, if you will.
If all else fails	Used to express that a specific action will be taken only when other options have been exhausted	If all else fails, we can always move to another city and start over.
If only	Used to express a wish that a situation were different or to express regret about something that cannot be changed	If only I had known about the traffic, I would have left earlier.
If the worst comes to the worst	Used to indicate what someone will do if the most unfavorable situation occurs	If the worst comes to the worst, we can always sell the house and move into a smaller apartment.

II. What is Whether?

Whether (pronounced /ˈwɛð.ər/) functions as a conjunction, used to express a doubt or choice between two possibilities.

She asked me whether I was interested in working for her.
Whether or not Daisy resigned from her job is none of my business.

III. How to Use the Structures If and Whether

Although we often see the word "If" used in conditional sentences, the structures If and Whether that we are exploring are also commonly used in reported speech. PREP will guide you through the use of If and Whether in indirect questions and the structure "Whether or not."

1. Indirect Questions with If and Whether

The expressions "If" and "Whether" can be utilized to turn direct inquiries into reported format, used to express a doubt or choice between two possibilities. Here’s the structure for this usage:

S + V + whether/if + S + V

For example:

John asked if his mother could pick him up after school.
Jenny and I wanted to know whether our class were going to eat out.

2. If and Whether with or not

The structures If and Whether can also mean “whether something is true or not” or “whether something is the case or not.” The formulas are:

S + V + whether/if + S + V + or not

S + V + whether or not + S + V

For example:

I called Harry to ask whether he got married or not.
Our team has to process the meeting whether or not the boss is here.

Note on Using the Structures Whether or and Whether or not:

"Whether or" is used to present two choices or alternatives regarding an event/action. Example: I don’t know whether Harry is laughing or crying.
"Whether or not" is used to express negation or conflicting information. Example: Whether or not Peter likes it, he will have to learn this subject.

IV. Distinguishing Between If and Whether

At first glance, you might think that "If" and "Whether" are the same, but they have some differences in usage. Let's take a look:

Distinguishing Between If and Whether

Similarities

Both "If" and "Whether" are used to introduce Yes/No questions in indirect speech. For example:

John asked Anna whether she felt well.
Jenny is not sure if they have decided.

Differences

After the verb "discuss," "Whether" is preferred over "If."
- We discussed whether he should be hired.
- They discussed whether to invest in the new idea.
After prepositions, only "Whether" can be used.
- Daisy talked about whether she should go or not.
- I looked into whether he should stay.
With the infinitive form of verbs, only "Whether" is used.
- Kathy can’t decided whether to buy the house or wait.
- Peter considered whether to give up the position or quit next month.
"Whether" is often used in more formal or diplomatic contexts, while "If" is typically used in casual and informal situations.
- Let me know whether Anna will be able to attend the meeting.
- Kathy asked if Sara had seen that film.

VI. Common Mistakes When Using If and Whether

In daily English communication, many people often encounter the following mistakes in the use of "If" and "Whether." Read through these common errors and remember them to avoid making similar mistakes:

Common Mistakes When Using If and Whether	Example
Using If before the Infinitive	Sara is not sure if to get a new telephone. ➡ ❌ Sara is not sure whether to get a new telephone. ➡ ✅
In Indirect Questions, Use Either:	Daisy can’t say either using Facebook is harmful or beneficial. ➡ ❌ Daisy can’t say whether using facebook is harmful or beneficial. ➡ ✅
Cannot Omit If and Whether in Indirect Questions:	Peter wants to find out the rooms have a phone and television or not. ➡ ❌ Peter wants to find out whether/if the rooms have a phone and television or not. ➡ ✅
Use If Directly Before Or Not:	Can you tell me if or not you are interested in studying abroad? ➡ ❌ Can you tell me whether or not you’re interested in studying abroad? ➡ ✅

VII. Exercises on the Structures If and Whether with Answers

After learning various theories about "If" and "Whether," let's practice with some exercises to reinforce our knowledge!

1. Exercises

Exercise 1: Fill in the blanks with the appropriate "If" or "Whether."

I don’t know ___Jenny is coming or not, she doesn’t mention the party.
Kathy considered___ to continue studying her major or take up a Marketing course.
Tell me___ John can come to the party or not.
Anna’s mother is still wondering ___she will choose the red car or the blue car.
Kathy called John to ask ____ he finished the report or not.

Exercise 2: Rewrite the sentences using the structures If and Whether.

“Do you want to eat this candy?”

➡ Sara asked John _______________________________________.

“Have you visited Korea?”

➡ Anna asked Peter _______________________________________.

“Does Jenny like coffee?”

➡ Harry wanted to know _______________________________________.

“Is Peter playing football?”

➡ Kathy wondered _______________________________________.

“Are you learning Japanese?”

➡ Daisy asked me _______________________________________.

2. Answer keys

Bài tập 1	Bài tập 2
If Whether If If Whether	Sara asked John if/whether he wanted to eat that candy. Anna asked Peter if/whether he had visited London. Harry wanted to know if/whether Jenny liked coffee. Kathy wondered if/whether Peter was playing football. Daisy asked me if/whether I was learning Japanese.

This concludes the detailed knowledge about "If" and "Whether," including their structures, usages, distinctions, and practical exercises. Be sure to follow PREP for more valuable English learning resources! If you have any more questions or need further practice, feel free to ask!

Master Tu Pham

Founder/CEO at Prep

Founder of Prep Smart Test Preparation Platform. With over 10 years of experience in teaching and test preparation, Mr. Tú has helped thousands of students achieve high scores in the IELTS exam. In addition, Mr. Tú Phạm is also a consulting expert in British Council programs and a speaker at many leading educational events, programs, and conferences.