Because vs Because of: How to Use Them Correctly

Because and because of are both used to explain reasons. However, they follow different grammatical structures. Understanding the difference between because vs because of will help you write more accurate sentences and avoid common grammar mistakes.

In this guide, you will learn their meanings, formulas, usage, sentence transformation rules, and practical exercises with answers.

Because vs Because of: Key Differences

Both expressions explain why something happens, but the main difference is what follows each expression.

Remember this basic rule:

• Because + subject + verb
• Because of + noun / noun phrase / gerund

Compare these examples:

• She was late because she missed the bus.
• She was late because of the missed bus.

Both sentences explain why she was late, but the grammatical structures after because and because of are different.

How to Use Because

Meaning of because

Because is a subordinating conjunction used to introduce a clause that explains the reason for an action, situation, or event.

The clause following because must contain a subject and a verb.

Structure of because

The two common sentence patterns are:

Pattern 1:

Because + subject + verb, main clause.

Examples:

• Because I was tired, I went to bed early.
• Because the weather was bad, we canceled the picnic.
• Because she studied hard, she passed the exam.

When the because-clause comes first, use a comma to separate it from the main clause.

Pattern 2:

Main clause + because + subject + verb.

Examples:

• I went to bed early because I was tired.
• We canceled the picnic because the weather was bad.
• She passed the exam because she studied hard.

When the because-clause comes after the main clause, a comma is usually unnecessary.

When to use because

Use because when you want to explain a reason using a complete clause.

Examples:

• Tom stayed at home because he had a fever.
• They took a taxi because they were in a hurry.
• I couldn’t attend the meeting because I had another appointment.
• The plants died because nobody watered them.

In each sentence, the word because is followed by a subject and a verb.

How to Use Because of

Meaning of because of

Because of is a prepositional expression used to introduce a reason. Unlike because, it is followed by a noun, a noun phrase, or a gerund rather than a complete clause.

Structure of because of

The basic structure is:

Because of + noun / noun phrase / gerund

Examples:

• The flight was delayed because of the storm.
• We couldn’t play outside because of the heavy rain.
• She succeeded because of her hard work.
• He was tired because of working late last night.

In these examples, the words following because of are nouns, noun phrases, or gerunds.

When to use because of

Use because of when the reason can be expressed as a noun or noun phrase.

Examples:

• The match was canceled because of bad weather.
• She couldn’t sleep because of the noise.
• The road was closed because of an accident.
• He improved his English because of regular practice.

You can also use a gerund after because of:

• The team won because of working together effectively.
• She was exhausted because of running for an hour.

The gerund functions as a noun in these examples.

Because vs Because of: How to Rewrite Sentences

One common English grammar exercise asks you to rewrite sentences using because or because of without changing their meaning.

To do this correctly, you need to change the grammatical structure of the reason.

Changing because to because of

When changing a sentence with because to one with because of, turn the reason clause into a noun phrase or gerund phrase.

Example 1

Original: We stayed indoors because it was raining heavily.

Rewritten: We stayed indoors because of the heavy rain.

Explanation: The clause it was raining heavily has been changed into the noun phrase the heavy rain.

Example 2

Original: She passed the exam because she studied hard.

Rewritten: She passed the exam because of her hard work.

Explanation: The clause describing her effort has been replaced with the noun phrase her hard work.

Example 3

Original: He was tired because he worked late.

Rewritten: He was tired because of working late.

Explanation: The verb worked has been changed to the gerund working.

Changing because of to because

When changing because of to because, expand the noun phrase into a clause containing a subject and a verb.

Example 1

Original: The flight was delayed because of the storm.

Rewritten: The flight was delayed because there was a storm.

Example 2

Original: She was absent because of her illness.

Rewritten: She was absent because she was ill.

Example 3

Original: The event was canceled because of the heavy rain.

Rewritten: The event was canceled because it rained heavily.

Important: When rewriting sentences, make sure the new sentence preserves the original meaning. You may need to change the wording or sentence structure rather than simply replacing one expression with the other.

Common Mistakes with Because and Because of

Although these expressions have similar meanings, they cannot always be used interchangeably.

Using a noun directly after because

Incorrect: We stayed home because the rain.

Correct: We stayed home because of the rain.

Alternatively, use a complete clause:

We stayed home because it was raining.

Explanation: Because must introduce a clause with a subject and a verb.

Using a complete clause directly after because of

Incorrect: She was late because of she missed the bus.

Correct: She was late because she missed the bus.

Alternatively:

She was late because of the missed bus.

Explanation: Because of is followed by a noun phrase or gerund, not a complete clause.

Forgetting to change the verb when using a gerund

Incorrect: He was exhausted because of he worked all night.

Correct: He was exhausted because he worked all night.

Alternatively:

He was exhausted because of working all night.

Explanation: If you use a verb after because of, it generally needs to be in the gerund form.

Confusing because with because of in sentence transformations

Incorrect: The match was canceled because the bad weather.

Correct: The match was canceled because of the bad weather.

Alternatively:

The match was canceled because the weather was bad.

Explanation: Choose the expression based on the grammatical structure that follows it.

Because vs Because of Exercises with Answers

Complete the exercises below to practise using because and because of correctly.

Exercise 1: Fill in the blanks

Choose because or because of to complete each sentence.

1. We canceled the trip ______ the heavy rain.
2. She stayed home ______ she was feeling sick.
3. The school was closed ______ the storm.
4. He failed the test ______ he didn’t study enough.
5. The flight was delayed ______ thick fog.
6. They were happy ______ they had won the competition.
7. The roads were slippery ______ the snow.
8. I couldn’t sleep ______ the loud music.
9. She improved her speaking skills ______ she practised every day.
10. The picnic was postponed ______ the bad weather.

Answers and explanations

1. because of — Followed by the noun phrase the heavy rain.
2. because — Followed by the clause she was feeling sick.
3. because of — Followed by the noun the storm.
4. because — Followed by the clause he didn’t study enough.
5. because of — Followed by the noun phrase thick fog.
6. because — Followed by the clause they had won the competition.
7. because of — Followed by the noun the snow.
8. because of — Followed by the noun phrase the loud music.
9. because — Followed by the clause she practised every day.
10. because of — Followed by the noun phrase the bad weather.

Exercise 2: Rewrite the sentences using the expression in brackets

Rewrite each sentence without changing its meaning.

1. Because she was tired, she went to bed early. (because of)
2. The match was canceled because of the rain. (because)
3. He passed the exam because he worked hard. (because of)
4. They couldn’t go out because of the storm. (because)
5. I was late because I missed the bus. (because of)

Suggested answers

1. She went to bed early because of her tiredness.
2. The match was canceled because it was raining.
3. He passed the exam because of his hard work.
4. They couldn’t go out because there was a storm.
5. I was late because of missing the bus.

Other answers may also be correct if they preserve the original meaning and use the required grammatical structure.

Exercise 3: Find and correct the mistakes

Each sentence contains a mistake involving because or because of. Rewrite it correctly.

1. She was absent because of she was sick.
2. We stayed inside because the heavy rain.
3. He couldn’t concentrate because of he was tired.
4. The flight was delayed because the fog.
5. They won the match because of they practised hard.

Answers and explanations

1. She was absent because she was sick.
   Use because before a complete clause.
2. We stayed inside because of the heavy rain.
   Use because of before a noun phrase.
3. He couldn’t concentrate because he was tired.
   Use because before the subject he and the verb was.
4. The flight was delayed because of the fog.
   Use because of before the noun the fog.
5. They won the match because they practised hard.
   Use because before the clause they practised hard.

Frequently Asked Questions

What is the difference between because and because of?

Because is followed by a subject and a verb, while because of is followed by a noun, noun phrase, or gerund.

Examples:

• I stayed home because I was sick.
• I stayed home because of my illness.

Both sentences explain the same general reason, but their grammatical structures differ.

Can because of be followed by a verb?

Yes, but the verb generally needs to take the gerund form (-ing) because it functions as a noun.

Correct: He was tired because of working late.

Incorrect: He was tired because of he worked late.

You can also rewrite the second sentence using because: He was tired because he worked late.

Can because and because of be used in the same sentence?

Yes, provided each expression is followed by the correct grammatical structure.

Example:

We canceled the outdoor event because the weather was bad and because of safety concerns.

Here, because the weather was bad is a clause, while because of safety concerns is a noun phrase.

Is because of more formal than because?

Neither expression is inherently more formal in every context. Both are common in spoken and written English. The choice mainly depends on the grammatical structure of the sentence.

How can I remember the difference between because and because of?

Remember these two patterns:

• Because + subject + verb
• Because of + noun / noun phrase / gerund

Check the words immediately following the expression to decide which one to use.

Understanding the difference between because and because of becomes easier with regular practice. Focus on the structure that follows each expression, and practise rewriting sentences to express the same reason in different ways.

Keywords:

• because and because of usage
• because vs because of exercises
• because and because of grammar rules
• because vs because of sentence transformation
• because of vs due to