Conjunctive and Complement Clauses in Persian

Overview

Complement clauses complete the meaning of verbs of thinking, knowing, saying, and believing. In Persian, they are introduced by که (ke, "that"), the most versatile conjunction in the language. At the B1 level, mastering complement clauses lets you express opinions, report knowledge, and ask indirect questions — crucial skills for intermediate communication.

The pattern is straightforward: main verb + که + subordinate clause. Verbs like فکر کردن (to think), دانستن (to know), گفتن (to say), and مطمئن بودن (to be sure) all take که-complements. Indirect questions drop که and use the question word directly.

How It Works

Main Verb	Pattern	Example
فکر کردن (think)	فکر می‌کنم که...	I think that...
دانستن (know)	می‌دانم که...	I know that...
گفتن (say)	گفت که...	He said that...
مطمئن بودن (be sure)	مطمئنم که...	I'm sure that...
امیدوار بودن (hope)	امیدوارم که...	I hope that...
باور کردن (believe)	باور می‌کنم که...	I believe that...

Indirect questions:

• نمی‌دانم چرا رفت. (I don't know why he left.)
• نمی‌دانم کجا رفته. (I don't know where he went.)
• پرسیدم آیا می‌آید. (I asked whether he would come.)

Examples in Context

Persian	English	Note
فکر می‌کنم که درست است.	I think that it's correct.	Opinion
می‌دانم که نمی‌آید.	I know that he won't come.	Knowledge
نمی‌دانم چرا رفت.	I don't know why he left.	Indirect question
مطمئنم که موفق می‌شوی.	I'm sure you'll succeed.	Certainty
امیدوارم که خوب باشی.	I hope you're well.	Hope
شنیدم که ازدواج کرده.	I heard he got married.	Reported info
نمی‌فهمم چی می‌گی.	I don't understand what you're saying.	Indirect question
باور نمی‌کنم که این‌طوری باشد.	I don't believe it's like this.	Disbelief
معلوم نیست کی می‌آید.	It's unclear when he'll come.	Impersonal
فکر نمی‌کنم درست باشه.	I don't think it's correct.	Colloquial

Common Mistakes

Omitting که when it is needed

• Wrong: فکر می‌کنم درسته (acceptable colloquially but formal register needs که)
• Right: فکر می‌کنم که درست است (formal)
• Why: In writing and formal speech, که is generally required. In casual speech, it is often dropped.

Using که for indirect questions

• Wrong: نمی‌دانم که چرا رفت
• Right: نمی‌دانم چرا رفت
• Why: Indirect questions typically do not use که — the question word directly follows the main verb.

Practice Tips

1. Express opinions: فکر می‌کنم که... (I think that...), به نظرم... (in my opinion...).
2. Practice indirect questions: نمی‌دانم + question word: نمی‌دانم کجاست (I don't know where it is), نمی‌دانم کیه (I don't know who it is).
3. Report information: شنیدم که... (I heard that...), خواندم که... (I read that...).

Related Concepts

• Relative Clauses with که — the same که in relative clause function