Topics
BeginnerComplement Clauses
How clauses function as subjects, objects, and complements in Spanish, English and Chinese.
Compare languages
Complement clauses are clauses that function as noun phrases. Spanish uses que + subjunctive/indicative. English uses that-clauses, infinitives, or -ing forms. Chinese uses 说/觉得/知道 + clause, often with 的 nominalization.
Overview
Complement clauses are subordinate clauses that function as noun phrases: subjects, objects, or predicative complements.
- Spanish: Uses que to introduce complement clauses. The subjunctive is required after verbs of volition, emotion, doubt, and necessity. Indicative is used after verbs of knowledge, perception, and certainty.
- English: Uses that-clauses, infinitive clauses, and -ing clauses. That is often deletable in informal contexts. Extraposition (moving a heavy subject to the end) is common.
- Chinese: Uses the clause directly as subject or object without special marking. 说 introduces reported speech. 觉得/认为/知道 take bare clauses as objects.
Spanish
Que + indicative (factual complements)
After verbs of knowledge, perception, certainty:
- Sé que vino. (I know that he came.)
- Veo que está cansado. (I see that he is tired.)
- Creo que tiene razón. (I think he is right.)
- Dijo que vendría. (He said he would come.)
- Me parece que es tarde. (It seems to me that it’s late.)
Que + subjunctive (non-factual complements)
After verbs of desire, command, emotion, doubt, necessity:
Desire:
- Quiero que vengas. (I want you to come.)
- Espero que llegues pronto. (I hope you arrive soon.)
Command:
- Mando que lo hagas. (I order you to do it.)
- Insisto en que estudies. (I insist that you study.)
Emotion:
- Me alegro de que hayas venido. (I’m glad you came.)
- Siento que estés enfermo. (I’m sorry you’re sick.)
Doubt:
- Dudo que sea verdad. (I doubt it’s true.)
- No creo que venga. (I don’t think he’ll come.)
Necessity:
- Es necesario que estudies. (It’s necessary that you study.)
- Conviene que vengas. (It’s advisable that you come.)
Infinitive complement (same subject)
When the subject of the main and subordinate clause is the same:
- Quiero ir. (I want to go.)
- Espero llegar pronto. (I hope to arrive soon.)
- Es importante estudiar. (It’s important to study.)
- Me alegra verte. (I’m glad to see you.)
Subject complement clause
Spanish allows pre-verbal subject clauses naturally:
- Que llueva es triste. (That it’s raining is sad.)
- Que no venga me preocupa. (That he’s not coming worries me.)
But extraposition is also common:
- Es triste que llueva. (It’s sad that it’s raining.)
De que vs que
After certain nouns and verbs, de is required:
- Me alegro de que vengas. (I’m glad that you’re coming.)
- Tengo miedo de que no llegue. (I’m afraid he won’t arrive.)
- La posibilidad de que llueva (the possibility that it will rain)
English
That-clauses
As object:
- I know that he came.
- She believes that he is right.
- He said that he was tired.
That-deletion (informal):
- I know Ø he came.
- She believes Ø he is right.
- He said Ø he was tired.
Note: That cannot be deleted after certain verbs:
- ❌ I replied Ø he was wrong. → I replied that he was wrong.
As subject (extraposition)
English prefers extraposition for subject clauses:
-
✅ It’s important that he study. (extraposed)
-
? That he study is important. (pre-verbal, awkward)
-
It’s sad that she left.
-
It’s likely that he’ll come.
-
It seems that he knows.
Infinitive complements
After want, need, hope, decide, etc.:
- I want to leave.
- She decided to stay.
- He hopes to win.
With object + infinitive:
- I want him to leave.
- She asked me to help.
-ing complements
- I enjoy reading.
- She admitted stealing it.
- He suggested going early.
Wh-clauses
- I don’t know what to do.
- She understands how it works.
- I wonder whether he will come.
For + to infinitive
- It’s important for him to study.
- I arranged for her to meet us.
Chinese
Bare clause as object
Chinese complement clauses appear without special marking:
- 我知道他来了。(I know he came.)
- 我觉得他很聪明。(I think he is smart.)
- 我认为你对。(I think you’re right.)
- 我希望他能来。(I hope he can come.)
说 for reported speech
说 introduces reported speech:
- 他说他很累。(He said he was tired.)
- 他说他不来了。(He said he wasn’t coming.)
Note: 说 is used only for speech verbs. For think/believe/know, it is omitted.
的 nominalization
- 他来的事让我很高兴。(His coming made me happy.)
- 我知道的是… (What I know is…)
Subject clause (pre-verbal)
Chinese allows subject clauses naturally:
- 他不来让我很担心。(That he’s not coming worries me.)
- 学习很重要。(Studying is important. — verb as subject)
让/叫/使 (causative complement)
- 我让他来。(I made him come.)
- 他叫我走。(He told me to leave.)
得 as complement marker
- 他说得很好。(He speaks very well. — complement of manner)
- 他跑得很快。(He runs very fast.)
Comparison at a glance
| Function | Spanish | English | Chinese |
|---|---|---|---|
| Factual object clause | que + indicative | that + clause | bare clause |
| Non-factual object clause | que + subjunctive | that + clause / infinitive | bare clause + 能/会 |
| Same subject infinitive | infinitive | to + infinitive | bare verb |
| Subject clause | que + clause | extraposed it + that-clause | clause directly as subject |
| Reported speech | dijo que | said that | 说 + clause |
| Causative | hacer que + subj | make + object + infinitive | 让/叫 + object + verb |
| Manner complement | — | — | verb + 得 + complement |
Examples
In Context
| Spanish | English | Chinese |
|---|---|---|
| Quiero que vengas. (subjunctive) | I want you to come. | 我想让你来。 |
| Es importante estudiar. / Es importante que estudies. | It’s important to study. / It’s important that you study. | 学习很重要。 |
| Dijo que estaba cansado. | He said (that) he was tired. | 他说他很累。 |
Common mistakes
-
English speakers learning Spanish: Quiero que vienes → Quiero que vengas (subjunctive)
-
Spanish speakers learning English: I want that you come → I want you to come
-
English speakers learning Chinese: 我知道说他来了 → 我知道他来了 (no 说 with 知道)
-
Chinese speakers learning English: I think he is right (okay) vs I think that he is right (formal)
Related topics
- Subjunctive: How mood encodes non-factuality
- Reported Speech: How indirect speech works
- Nominalization: How clauses become noun-like
- Word Order: How extraposition works
Examples
I know that he came
Sé que vino (indicative)
I want him to come
Quiero que venga (subjunctive)
It's important that he study
Es importante que estudie (subjunctive)
I think he is smart
Creo que es inteligente (indicative)
I'm glad that he came
Me alegro de que haya venido (subjunctive)
He said that he was tired
Dijo que estaba cansado
Subject complement clause
Que llueva es triste (indicative/subjunctive)
Extraposition
Es probable que venga (common)
Examples
I know that he came
I know that he came
I want him to come
I want him to come
It's important that he study
It's important that he study (subjunctive)
I think he is smart
I think (that) he is smart
I'm glad that he came
I'm glad (that) he came
He said that he was tired
He said (that) he was tired
Subject complement clause
That it's raining is sad / It's sad that it's raining
Extraposition
It's likely that he'll come (extraposition required)
Examples
I know that he came
我知道他来了
I want him to come
我想让他来
It's important that he study
他学习很重要
I think he is smart
我觉得他很聪明
I'm glad that he came
他来了，我很高兴
He said that he was tired
他说他很累
Subject complement clause
下雨很让人难过
Extraposition
他可能会来
Comparison at a glance
| Grammar concepts | Spanish | English | Chinese |
|---|---|---|---|
| I know that he came | Sé que vino (indicative) | I know that he came | 我知道他来了 |
| I want him to come | Quiero que venga (subjunctive) | I want him to come | 我想让他来 |
| It's important that he study | Es importante que estudie (subjunctive) | It's important that he study (subjunctive) | 他学习很重要 |
| I think he is smart | Creo que es inteligente (indicative) | I think (that) he is smart | 我觉得他很聪明 |
| I'm glad that he came | Me alegro de que haya venido (subjunctive) | I'm glad (that) he came | 他来了，我很高兴 |
| He said that he was tired | Dijo que estaba cansado | He said (that) he was tired | 他说他很累 |
| Subject complement clause | Que llueva es triste (indicative/subjunctive) | That it's raining is sad / It's sad that it's raining | 下雨很让人难过 |
| Extraposition | Es probable que venga (common) | It's likely that he'll come (extraposition required) | 他可能会来 |
Select at least one language to view comparisons
Side-by-side comparison
| Grammar concepts | Spanish | English | Chinese |
|---|---|---|---|
| I know that he came | Sé que vino (indicative) | I know that he came | 我知道他来了 |
| I want him to come | Quiero que venga (subjunctive) | I want him to come | 我想让他来 |
| It's important that he study | Es importante que estudie (subjunctive) | It's important that he study (subjunctive) | 他学习很重要 |
| I think he is smart | Creo que es inteligente (indicative) | I think (that) he is smart | 我觉得他很聪明 |
| I'm glad that he came | Me alegro de que haya venido (subjunctive) | I'm glad (that) he came | 他来了，我很高兴 |
| He said that he was tired | Dijo que estaba cansado | He said (that) he was tired | 他说他很累 |
| Subject complement clause | Que llueva es triste (indicative/subjunctive) | That it's raining is sad / It's sad that it's raining | 下雨很让人难过 |
| Extraposition | Es probable que venga (common) | It's likely that he'll come (extraposition required) | 他可能会来 |
Select at least one language to view comparisons
Examples in context
I know that he came
Spanish
Sé que vino (indicative)
English
I know that he came
Chinese
我知道他来了
I want him to come
Spanish
Quiero que venga (subjunctive)
English
I want him to come
Chinese
我想让他来
It's important that he study
Spanish
Es importante que estudie (subjunctive)
English
It's important that he study (subjunctive)
Chinese
他学习很重要
I think he is smart
Spanish
Creo que es inteligente (indicative)
English
I think (that) he is smart
Chinese
我觉得他很聪明
I'm glad that he came
Spanish
Me alegro de que haya venido (subjunctive)
English
I'm glad (that) he came
Chinese
他来了，我很高兴
He said that he was tired
Spanish
Dijo que estaba cansado
English
He said (that) he was tired
Chinese
他说他很累
Subject complement clause
Spanish
Que llueva es triste (indicative/subjunctive)
English
That it's raining is sad / It's sad that it's raining
Chinese
下雨很让人难过
Extraposition
Spanish
Es probable que venga (common)
English
It's likely that he'll come (extraposition required)
Chinese
他可能会来
Select at least one language to view comparisons
Key Takeaways
Spanish: Uses que to introduce complement clauses. The subjunctive is required after verbs of volition, emotion, doubt, and necessity. Indicative is.
English: Uses that-clauses, infinitive clauses, and -ing clauses. That is often deletable in informal contexts. Extraposition (moving a heavy subject.
Chinese: Uses the clause directly as subject or object without special marking. 说shuō introduces reported speech. 觉jué得dé/认rèn为wéi/知zhī道dào take bare. Chinese uses 说/觉得/知
Key concepts compared: I know that he came, I want him to come, It's important that he study.
Frequently Asked Questions
Why does Spanish require the subjunctive in complement clauses where English uses the indicative?
How does Chinese omission of complementizers differ from English and Spanish?
Why does English allow 'that'-deletion in informal speech but Spanish does not allow 'que'-deletion?
References
- Nueva gramática de la lengua española — Real Academia Española / Asociación de Academias de la Lengua Española, 2010
- The Cambridge Grammar of the English Language — Huddleston & Pullum, Cambridge University Press, 2002
- A Comprehensive Grammar of the Modern Chinese Language — Li & Thompson, 1981
Read this first
Last updated: June 4, 2026