Because vs Because Of: Key Differences with Examples

Introduction

Do you ever pause before writing “because” or “because of”? You are not alone. Even advanced English learners often confuse these two structures. The difference is simple once you know the rule: because introduces a full clause (subject + verb), while because of introduces a noun or noun phrase. Mastering this distinction will make your writing and speaking much clearer. In this post, we will break down the rules, show you dozens of examples, and help you avoid the most common mistakes.

What Is “Because” and “Because Of”?

Because is a subordinating conjunction. It connects a reason to a result and is always followed by a subject and a verb (a full clause). For example: I stayed home because I was sick.

Because of is a two-word preposition. It is followed by a noun, a noun phrase, or a gerund (-ing form). For example: I stayed home because of my illness.

The key difference is grammatical: because + clause, because of + noun.

Rules

1. Use “because” + subject + verb. Example: The match was cancelled because it rained.
2. Use “because of” + noun or noun phrase. Example: The match was cancelled because of the rain.
3. Never put a verb directly after “because of.” Wrong: because of it rained. Correct: because of the rain.
4. You can use “because” at the beginning of a sentence. Example: Because I was late, I missed the bus. (Note the comma after the clause.)
5. “Because of” can also begin a sentence. Example: Because of the traffic, we arrived late. (Again, add a comma after the phrase.)
6. After “because of,” you can use a gerund (-ing form) as a noun. Example: He succeeded because of working hard.

How to Use It

Follow these simple steps to choose correctly every time:

1. Identify what follows the word. Look at the next word or phrase. Is it a verb (e.g., “is,” “arrived,” “wanted”)? Or is it a noun (e.g., “the weather,” “my boss,” “a problem”)?
2. If it is a verb (or a subject + verb), use “because.” Example: She cried because she lost her phone. (Here, “she lost” is a subject + verb.)
3. If it is a noun or noun phrase, use “because of.” Example: She cried because of the loss of her phone. (Here, “the loss” is a noun phrase.)
4. Test by substitution. Try replacing the phrase with “due to.” If it sounds natural, “because of” is correct. Example: He was tired because of the long drive. (He was tired due to the long drive.) Works.
5. Practice with both structures. Write a sentence with “because” and then rewrite it using “because of.” This builds muscle memory. Example: I passed the exam because I studied hard. → I passed the exam because of hard study.

Examples in Sentences

• Because the store was closed, we went home.
• We went home because the store was closed.
• We went home because of the closed store.
• He didn’t come to the party because he felt unwell.
• He didn’t come to the party because of his illness.
• The flight was delayed because there was a storm.
• The flight was delayed because of the storm.
• She got a promotion because she worked efficiently.
• She got a promotion because of her efficient work.
• Because the internet was down, I couldn’t send the email.
• I couldn’t send the email because of the internet outage.
• They cancelled the picnic because it was too windy.
• They cancelled the picnic because of the strong wind.

Common Mistakes

• Mistake 1: ❌ I left early because of I was tired.
  ✅ I left early because I was tired. (Use “because” before a subject + verb.)
• Mistake 2: ❌ She passed the test because she studied hard. (This is actually correct! But some learners overcorrect and write: ❌ She passed the test because of she studied hard.)
  ✅ She passed the test because she studied hard. (Or) She passed the test because of her hard study.
• Mistake 3: ❌ He was late because the traffic.
  ✅ He was late because of the traffic. (After “because of,” use a noun phrase, not a clause.)
• Mistake 4: ❌ Because of it was raining, we stayed inside.
  ✅ Because it was raining, we stayed inside. (Or) Because of the rain, we stayed inside.
• Mistake 5: ❌ I like him because of his honesty is admirable.
  ✅ I like him because his honesty is admirable. (Or) I like him because of his admirable honesty.

Quick Summary

• Because → conjunction → followed by a subject + verb (a clause). Example: We stayed home because it snowed.
• Because of → preposition → followed by a noun or noun phrase. Example: We stayed home because of the snow.
• Both can start a sentence, but remember to use a comma after the clause or phrase.
• Use a gerund after “because of” if you need a verb form acting as a noun. Example: He improved because of practicing daily.
• When in doubt, check if the next word is a verb (use “because”) or a noun (use “because of”).

Practice Exercises

Fill in the blanks with because or because of.

1. We missed the train __________ the delay on the subway.
2. I couldn’t sleep __________ the neighbours were playing loud music.
3. She got the job __________ her excellent qualifications.
4. The picnic was ruined __________ it rained all afternoon.
5. He passed the driving test __________ practicing every day.

Answers:

1. because of (the delay = noun phrase)
2. because (the neighbours were playing = subject + verb)
3. because of (her excellent qualifications = noun phrase)
4. because (it rained = subject + verb)
5. because of (practicing = gerund acting as a noun)

Conclusion

Understanding the difference between “because” and “because of” will instantly improve your grammar accuracy. Remember: because + clause, because of + noun. Practice rewriting sentences from one form to the other, and soon it will become automatic. Bookmark this page and come back whenever you need a quick reminder.

FAQ

1. Can I use “because” at the beginning of a sentence?

Yes, absolutely. When you start a sentence with “because,” you create a dependent clause. Add a comma after that clause before the main clause. Example: Because I was tired, I went to bed early. This is perfectly correct in formal and informal English.

2. Is “because of” always followed by a noun?

Yes, because of is a preposition and must be followed by a noun, a noun phrase, or a gerund (which functions as a noun). You cannot put a full verb after it. For example: He left because of the noise. (noun) or He left because of feeling sick. (gerund).

3. What is the difference between “because of” and “due to”?

Technically, “due to” should modify a noun (e.g., The cancellation was due to rain), while “because of” modifies a verb (e.g., The event was cancelled because of rain). However, in everyday English, many native speakers use them interchangeably. For B1–B2 learners, it is safer to stick with “because of” for reasons and “due to” after the verb “to be.”

4. Can I use “because” and “because of” in the same sentence?

Yes, but it can sound awkward if overused. A natural example: I was happy because I passed the test, and I was happy because of my friends’ support. Just be careful not to create a run-on sentence. Keep each reason clear and separate.