Why ในRelative Adverbs

Relative Adverb Series

Relative Adverbs: Common Noun Phrases Used with "Why"

"Why" is a relative adverb used after nouns expressing a reason. (ใช้เชื่อม Relative Clause เพื่ออธิบายเหตุผล)

1. Reason

Please tell me the reason why you were late.

2. Main reason

Heavy traffic is the main reason why I chose to stay home.

3. One reason

That is one reason why we need to save energy.

4. Another reason

There is another reason why this plan might fail.

5. Only reason

Money is the only reason why he accepted the job.

6. Possible reason

Stress is one possible reason why she feels unwell.

7. Important reason

Good health is an important reason why people exercise.

8. Real reason

Nobody knows the real reason why they left early.

9. Reasons

She listed the reasons why the project was successful.

10. No reason

There is no reason why we cannot finish this today.

11. Good reason

There is a good reason why she resigned.

12. Simple reason

The simple reason why he refused was his busy schedule.

13. Exact reason

I don't know the exact reason why the meeting was canceled.

Grammar Tip

Why is a relative adverb that refers to a reason.
(Why เป็น Relative Adverb ใช้แทนคำบอกเหตุผล)
why = for which (used in formal English e.g., The reason for which...)

Word / Phrase	Meaning
Reason	เหตุผล
Main reason	เหตุผลหลัก
One reason	เหตุผลหนึ่ง
Another reason	อีกเหตุผลหนึ่ง
Only reason	เหตุผลเดียว
Possible reason	เหตุผลที่เป็นไปได้
Important reason	เหตุผลสำคัญ
Real reason	เหตุผลที่แท้จริง
Reasons	เหตุผลต่างๆ (พหูพจน์)
No reason	ไม่มีเหตุผล
Good reason	เหตุผลอันควร / เหตุผลที่ดี
Simple reason	เหตุผลง่ายๆ / เหตุผลสั้นๆ
Exact reason	เหตุผลที่แน่ชัด

Grammar Note: In modern English, "the reason why", "the reason that", and "the reason" are all acceptable. However, "the reason why" is the most common in everyday English.