因: Formal Cause in Chinese
因
因 is a concise formal preposition introducing the reason for a following event, common in notices, reports, and written explanations. The whole 因 phrase precedes the result predicate. 因 cannot take aspect particles, cannot follow the result as an afterthought, and must have an explicit cause as its object.
Published July 23, 2026
Reviewed July 23, 2026
01 / PATTERN
See the Structure
MODEL
Subject + 因 + Cause + Predicate
Read the structure
因 is a concise formal preposition introducing the reason for a following event, common in notices, reports, and written explanations. The whole 因 phrase precedes the result predicate. 因 cannot take aspect particles, cannot follow the result as an afterthought, and must have an explicit cause as its object. Keep the model Subject + 因 + Cause + Predicate visible while you compare each sentence.
昨天她因病请假。
She took sick leave yesterday because of illness.
Choose the right context
Give a concise reason in formal writing. Use in notices such as 因病请假 or 因故取消. Link a stated cause to a following result.
比赛因大雨取消了。
The match was canceled because of heavy rain.
Respect the boundary
Do not attach 了 to 因. Do not omit the cause after 因. Do not place the 因 phrase after the result predicate.
她因了病请假。
(She because-le illness took leave.)
Repair the pattern
了 is attached to the cause preposition: 因 introduces the cause and cannot take the aspect particle 了. The preposition lacks a cause: 因 must be followed by an explicit cause before the result predicate.
她因病请假。
Use the repaired structure without changing the intended meaning.
02 / MAP
Read the Sentence
Read from left to right and notice the job performed by each part. The labels describe this example; they are not a rule that every Chinese sentence must copy.
昨天她因病请假。
She took sick leave yesterday because of illness.
昨天
Subject
This part occupies the Subject position in the model pattern.
她
因
This part occupies the 因 position in the model pattern.
因病请假
Cause
This part occupies the Cause position in the model pattern.
03 / EXAMPLES
Examples You Can Reuse
Keep the structure stable while changing the people, objects, times, or conditions. Pinyin is shown as reading support; use the Chinese sentence and translation to confirm the grammar relationship.
昨天她因病请假。
She took sick leave yesterday because of illness.
比赛因大雨取消了。
The match was canceled because of heavy rain.
他因出门太晚而迟到了。
He was late because he left home too late.
04 / LIMITS
When to Use It — and When Not To
Use it when
- Give a concise reason in formal writing.
- Use in notices such as 因病请假 or 因故取消.
- Link a stated cause to a following result.
Do not use it when
- Do not attach 了 to 因.
- Do not omit the cause after 因.
- Do not place the 因 phrase after the result predicate.
05 / REPAIR
Compare Right and Wrong
Compare the smallest meaningful change. Each explanation identifies a placement, scope, form, or clause relationship instead of treating the whole sentence as one undifferentiated mistake.
她因了病请假。
她因病请假。
了 is attached to the cause preposition
因 introduces the cause and cannot take the aspect particle 了.
比赛因取消了。
比赛因大雨取消了。
The preposition lacks a cause
因 must be followed by an explicit cause before the result predicate.
她因了病请假。
因 introduces the cause and cannot take the aspect particle 了.
比赛因取消了。
因 must be followed by an explicit cause before the result predicate.
06 / PRACTICE
Practice the Grammar Point
Complete three short tasks in order: judge the pattern, repair a common error, and build the sentence. Feedback is fixed and reviewed, so these activities do not use a checker allowance.
1. Judge the sentence
2. Choose the correction
3. Build the sentence
Build a complete sentence with 因.
07 / APPLY
Apply It in Your Sentence
Write one original sentence with 因. Your draft moves to the checker through this browser session, selects this grammar point as the first review focus, and waits for you to submit.
08 / QUESTIONS
因: Formal Cause Questions
How is 因 different from 因为?
因 is more concise and formal, while 因为 is common in both speech and writing and can introduce a full clause.
Can 因 take a clause?
It can introduce a compact noun phrase or event expression that functions as the cause.
09 / SOURCES
Sources and Review Notes
These references support different parts of the lesson. GF0025-2021 supports level placement only; professional grammar works support the explanation, limits, examples, and cross-checks. Their inclusion does not imply endorsement.
Chinese Proficiency Grading Standards for International Chinese Language Education (GF0025-2021)
Ministry of Education and State Language Commission · Ministry of Education of the PRC · 2021
Locator: GF0025-2021 Appendix A, Level 6 item 【六17】, 介词：因
Supports placement in HSK 6; it does not independently establish the usage explanation.
Official sourceA Reference Grammar of Chinese
Huang, Shi and Li · Cambridge University Press · 2022
Locator: Chapter 13, §13.4, semantic classification of prepositions; Chapter 14, §14.8, causative and purposive complex sentences
Supports pre-predicate causal PPs and the formal reason-to-result relation expressed by 因.
Official source10 / CONTINUE
Continue with a Connected Rule
Compare
（因）……，故……因…故…: Formal Cause and Result
Compare this lesson with 因……故…… pairing a formal cause with its result; both belong to formal cause, purpose, time, and location frames, but they organize a different sentence role or discourse job.
Compare
……，以……以: Introducing a Formal Purpose
Compare this lesson with clause-final 以 introducing a formal purpose; both belong to formal cause, purpose, time, and location frames, but they organize a different sentence role or discourse job.
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于于: Formal Time and Location
Compare this lesson with 于 introducing formal time, location, range, or comparison; both belong to formal cause, purpose, time, and location frames, but they organize a different sentence role or discourse job.
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因为…所以因为...所以 (Because... So)
Continue with the reviewed follow-up lesson to apply this pattern inside a broader, explicitly connected grammar construction.
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