Introduction
Do you ever pause mid-sentence, wondering whether to write “due to” or “because of”? You are not alone! Even advanced English learners frequently mix up these two phrases. While they both express cause and reason, they follow different grammar rules and carry different levels of formality. In this guide, you will learn exactly when to use each one, how to structure your sentences correctly, and how to avoid the most common ESL errors.
What Is “Due To” vs “Because Of”?
Both “due to” and “because of” are prepositional phrases that explain why something happens. They answer the question “Why?” in a sentence. However, the key difference lies in their grammatical roles.
“Because of” is an adverbial prepositional phrase. It modifies a verb, an adjective, or an entire clause. It tells us why an action occurred.
“Due to” is an adjectival prepositional phrase. It modifies a noun or a pronoun. It tells us why a noun exists or has a certain quality. In simple terms, “due to” usually follows the verb “to be” (is, are, was, were).
Think of it this way: “because of” answers “Why did it happen?” while “due to” answers “What caused it?”
Rules
Here are the golden rules to master this tricky grammar point. Follow these, and you will never confuse them again!
- Rule 1: “Because of” always follows a verb or clause. It explains why an action happened. Example: The match was cancelled because of rain. (The verb “was cancelled” is explained.)
- Rule 2: “Due to” follows the verb “to be” (is, am, are, was, were, been). It modifies the subject noun. Example: The cancellation was due to rain. (The noun “cancellation” is described.)
- Rule 3: “Due to” can also follow a noun directly. Example: Flight delays due to weather are common. Here, “due to” acts like an adjective modifying “delays.”
- Rule 4: In formal writing, do not start a sentence with “due to.” It sounds awkward and is often grammatically incorrect. Instead, use “because of” or “owing to.”
- Rule 5: “Because of” is more common in everyday speech and informal writing. “Due to” is preferred in academic, business, and official contexts.
- Rule 6: If you can replace the phrase with “caused by” and the sentence still makes sense, use “due to.” If you can replace it with “as a result of,” use “because of.”
How to Use It
Follow this simple step-by-step process to choose the correct phrase every time.
Step 1: Identify the word being modified
Look at the word that comes before the phrase. Is it a noun, or is it a verb/adjective?
Step 2: Apply the “to be” test
If the phrase follows a form of “to be” (is, was, were), you can usually use either, but “due to” is safer. Example: His success was due to hard work. (Correct) vs. His success was because of hard work. (Acceptable but less formal).
Step 3: Use the “caused by” trick
Rewrite your sentence mentally. If “caused by” fits naturally, choose “due to.” If not, choose “because of.”
- The accident was caused by fog. → The accident was due to fog. ✅
- He stayed home caused by illness. → This sounds wrong! → He stayed home because of illness. ✅
Step 4: Check the formality level
For essays, reports, or job applications, use “due to.” For casual conversations, emails to friends, or social media, “because of” is perfect.
Examples in Sentences
Here are 12 sentences showing correct usage. Pay attention to the bolded grammar points.
- The outdoor concert was cancelled because of the thunderstorm.
- The cancellation was due to the thunderstorm.
- She missed her appointment because of heavy traffic.
- Her absence was due to a family emergency.
- We arrived late because of the train delay.
- The train delay was due to a signal failure.
- He failed the exam because of lack of preparation.
- His failure was due to lack of preparation.
- Many businesses closed because of the economic crisis.
- The economic crisis was due to poor financial policies.
- I couldn’t sleep because of the noisy neighbours.
- Flight cancellations due to snow are expected tomorrow.
Common Mistakes
Let’s fix the most frequent errors ESL learners make. Avoid these traps!
- ❌ Wrong: The delay was because of technical issues.
✅ Correct: The delay was due to technical issues. (After “was,” use “due to.”) - ❌ Wrong: Due to the rain, we stayed inside.
✅ Correct: Because of the rain, we stayed inside. (At the start of a sentence, “because of” is better.) - ❌ Wrong: She succeeded due to her determination.
✅ Correct: She succeeded because of her determination. (After a verb like “succeeded,” use “because of.”) - ❌ Wrong: The project failed due to the manager left.
✅ Correct: The project failed because of the manager’s departure. (You cannot follow “due to” with a full clause; use a noun.) - ❌ Wrong: He was tired because of the long journey, which was because of the strike.
✅ Correct: He was tired because of the long journey, which was due to the strike. (Second part follows “was,” so use “due to.”)
Quick Summary
- “Because of” = adverbial phrase → modifies verbs → answers “Why did it happen?” → informal and formal use.
- “Due to” = adjectival phrase → modifies nouns → follows “to be” → more formal.
- Use the “caused by” test: If “caused by” fits, use “due to.”
- Do not start a sentence with “due to” in formal writing.
- Both phrases must be followed by a noun or noun phrase, not a full clause.
- When in doubt, choose “because of” for actions and “due to” for states of being.
Practice Exercises
Test your knowledge! Fill in the blanks with either “due to” or “because of.” Answers are below.
- The picnic was postponed __________ the bad weather.
- Her promotion was __________ her excellent performance.
- He couldn’t hear the teacher __________ the noise.
- The flight delay was __________ a technical fault.
- __________ the holiday, the office will be closed.
Answers:
- because of (after verb “was postponed”)
- due to (after “was”)
- because of (after verb “couldn’t hear”)
- due to (after “was”)
- Because of (starting a sentence)
Conclusion
Mastering “due to” vs “because of” is a small change that makes a big difference in your English accuracy. Remember: “because of” explains actions, while “due to” describes nouns and states. Practice the “caused by” trick, check your formality level, and soon this choice will feel automatic. Keep practicing, and your writing will become clearer and more professional!
FAQ
1. Can “due to” and “because of” ever be used interchangeably?
Yes, but only when they follow the verb “to be.” For example: The delay was due to traffic and The delay was because of traffic are both acceptable. However, “due to” is more formal. In all other positions, they are not interchangeable.
2. Is it ever correct to start a sentence with “due to”?
Strictly speaking, no. Many style guides recommend against it. Starting with “because of” is always safer and more natural. If you want to start with “due to,” rewrite the sentence so that “due to” follows a noun or the verb “to be.”
3. What is the difference between “due to” and “owing to”?
“Owing to” is a synonym for “because of” and is equally formal. It is more common in British English. Example: Owing to the strike, trains were cancelled. You can use it exactly like “because of,” but it sounds more sophisticated.
4. Can I use “due to” with a full clause (subject + verb)?
No. “Due to” must be followed by a noun or noun phrase. If you need to use a full clause, use “because” or “due to the fact that.” Example: The event was cancelled due to the fact that it rained. However, this phrasing is wordy, so “because it rained” is better.