Understanding Spoken and Written Persian

A few days ago, I shared a short Persian grammar lesson about something very useful: in Persian, we don't always need to say the subject pronoun because the ending of the verb can already tell us who is doing the action.

In that video, I used:

میدونم — midunam — I know

And that led to some interesting comments.

One person commented:

دونم ❌ دانم ✅

And, another learner asked whether it should actually be میدانم — midānam.

And I was actually very happy to see these comments, because they give us the perfect opportunity to talk about something every Persian learner eventually needs to understand:

The Persian you hear in everyday conversation is not always the same as the Persian you see in formal writing.

So, is it میدانم or میدونم?

The short answer: both exist.

But to understand why, we need to talk about spoken Persian (فارسی گفتاری), written Persian (فارسی نوشتاری), and the role that formality and register play in Persian.

Persian is not simply divided into two completely separate languages

Before we continue, I want to make one thing clear.

The linguistic reality is more complicated than simply saying, "Persian has two forms."

We can talk about spoken Persian (فارسی گفتاری) and written Persian (فارسی نوشتاری). We can also talk about more formal Persian (فارسی رسمی) and more informal or colloquial Persian (فارسی غیررسمی / فارسی محاورهای).

These categories overlap, but they are not exactly the same thing.

For example, writing does not always have to be formal. Think about texting your Iranian friend. You may be writing Persian, but you might write in a way that closely represents how you would actually speak:

نمیدونم، شاید فردا بیام.
I don't know, maybe I'll come tomorrow.

So for the purpose of this article, I'm going to simplify a much bigger linguistic subject and concentrate mainly on the distinction that matters most to a beginning or intermediate Persian learner:

the more standard/formal forms you frequently encounter in writing, and the colloquial forms you frequently hear in everyday speech.

This distinction between formal/written and spoken/colloquial varieties is also discussed in the Persian Online teaching materials developed at the University of Texas at Austin. Their materials describe Persian as having important differences between formal and informal usage and provide systematic examples of changes that occur in colloquial Persian.

Read: Persian Online — Diglossia (University of Texas at Austin)

Something Iranian children discover when they go to school

If you grew up speaking Persian in Iran, there is an interesting experience you probably don't even think about anymore.

Before school, you learn Persian primarily by listening to the people around you.

Your parents don't sit beside your crib and explain:

"Today, we're going to study colloquial phonological changes." 😂

You simply learn to speak.

So imagine a child who has spent the first six years of life calling bread:

نون — nun

Then they go to school and learn to read and write, and suddenly they meet:

نان — nān

They have been saying:

اومدم — umadam — I came

And now they encounter the standard written form:

آمدم — āmadam

They know:

خونه — khune — house/home

And learn to write:

خانه — khāne

And, of course, they may normally say:

میدونم — midunam — I know

while learning the standard written form:

میدانم — midānam

The child hasn't discovered that everybody around them was "speaking Persian incorrectly."

They are learning that Persian changes according to context, medium, and register.

So why does دان become دون?

This isn't just something that randomly happened to the verb دانستن — dānestan — to know.

There are systematic sound changes associated with colloquial Persian (فارسی محاورهای).

One particularly recognizable pattern in colloquial Tehrani Persian is the change of ān toward un in many words.

For example:

Standard / more formal form	Common colloquial form
نان — nān	نون — nun
خانه — khāne	خونه — khune
جان — jān	جون — jun
دانستن — dānestan	دونستن — dunestan

This /ān/ → /un/ pattern is specifically documented in the University of Texas at Austin's Persian Online materials on colloquial Persian. Their examples include دانستن → دونستن.

Read: Persian Online — Colloquial Persian verb changes (University of Texas at Austin)

However, this does not mean that every occurrence of ان / ān automatically becomes ون / un. These patterns need to be learned through vocabulary, exposure, and familiarity with spoken Persian.

So: میدانم or میدونم?

Let's return to the comment that started this conversation.

In standard Persian, particularly in formal writing, you will encounter:

میدانم — midānam

In everyday colloquial Persian, you will very commonly hear:

میدونم — midunam

And the pattern continues through the conjugation:

Standard / formal	Common spoken / colloquial
میدانم	میدونم
میدانی	میدونی
میداند	میدونه
میدانیم	میدونیم
میدانید	میدونید / میدونین
میدانند	میدونن

So saying:

"دونم is wrong and دانم is correct"

doesn't really capture what is happening linguistically.

میدونم is not simply a mistake made by people who don't know that the verb is دانستن.

It is a normal colloquial form used by Persian speakers.

But does that mean میدانم is wrong in conversation?

No.

This is another distinction I want Persian learners to understand.

If you're sitting in a restaurant with an Iranian friend and say:

من میدانم؛ تو نمیدانی.

they are not going to stare at you wondering what language you're speaking. 😂

It is Persian. They understand it.

However, in a relaxed everyday conversation, consistently choosing standard or highly formal forms can make your speech sound more formal, careful, literary, or "bookish" than the language people would ordinarily use in that context.

An Iranian friend in the same situation would be very likely to say:

من میدونم، تو نمیدونی.

That difference is important.

Language learning isn't only about asking:

"Can a Persian speaker understand this sentence?"

Eventually, we also want to ask:

"How would Persian speakers normally say this in this particular situation?"

Written Persian (فارسی نوشتاری) does not always mean formal Persian (فارسی رسمی)

This is where things become particularly interesting.

You may have noticed Iranians texting things like:

کجایی؟
دارم میام.
نمیدونم.
میخوای بریم؟

Technically, you are looking at written language (زبان نوشتاری) because someone has written it down.

But stylistically, it represents spoken/colloquial Persian (فارسی گفتاری / محاورهای).

This is one reason I don't want you to memorize a rule saying:

written = formal
spoken = informal

Real language isn't quite that tidy.

You can write colloquially, especially in texts, messages, dialogue, comments, and social media.

And you can speak very formally—for example, in a speech, a formal presentation, a news context, or certain ceremonial situations.

What matters is the register (گونه / سبک زبانی) appropriate to the situation.

 

Why do I teach میدونم on social media?

So now you know why I said میدونم — midunam in that video.

It was intentional.

A major goal of Shirin Persian School is to help you communicate with Persian speakers.

If you're learning Persian because your partner is Iranian, your parents or grandparents speak Persian, you have Iranian friends, you're travelling, or you simply want to participate in everyday Persian conversations, then you need exposure to the language people actually use around you.

That's why a lot of my short social-media lessons emphasize spoken Persian (فارسی گفتاری) and colloquial Persian (فارسی محاورهای).

When I'm teaching those forms on Instagram or YouTube, I often use an accessible Latin-letter transliteration:

میدونم — midunam

I don't necessarily use the International Phonetic Alphabet (IPA / الفبای آوانگاری بینالمللی) in every Reel or Short because not every learner can read IPA, and short social-media lessons need to remain accessible.

In longer materials on my website, however, I can give you more information: the Persian spelling, the spoken form, transliteration or IPA where appropriate, and explanations of the relationship between them.

Should Persian learners learn spoken Persian (فارسی گفتاری) or formal Persian (فارسی رسمی)?

My answer is:

I want you to be exposed to both.

The balance depends on why you are learning Persian.

In my classes, I generally place a strong emphasis on spoken Persian when a student's goal is everyday communication.

But I don't want you to know only spoken Persian.

Imagine studying for months and learning:

میدونم، میخوام، خونه، نون

and then opening a Persian book and encountering:

میدانم، میخواهم، خانه، نان

I don't want you to think:

"Wait. What are all these new words?"

They aren't necessarily new words.

You are seeing forms associated with a different register or context.

But the reverse problem matters just as much.

I don't want you to spend months learning only:

میدانم، میخواهم، خانه، نان

and then go to your first Persian مهمونی — mehmuni — party/gathering and think:

"What language are these people speaking?!" 😂

That is why exposure to both matters.

Your reason for learning Persian should determine the balance

Not every Persian learner needs exactly the same balance.

If your main goal is talking with your Iranian partner, friends, relatives, or in-laws, spoken Persian (فارسی گفتاری) deserves a major place in your learning.

If you want to read Persian literature, poetry, academic writing, historical material, or formal media, then written Persian (فارسی نوشتاری) and more formal registers become particularly important.

If you want to do both—and many of my students eventually do—you need to learn to recognize how Persian moves between these varieties.

It may feel difficult at first.

But there is also good news.

As you begin recognizing recurring patterns, forms that initially look unrelated start connecting in your mind:

نان ↔ نون
خانه ↔ خونه
میخواهم ↔ میخوام
میدانم ↔ میدونم

Instead of memorizing two completely separate languages, you gradually learn how Persian changes according to the situation in which it is being used.

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So, which one is correct?

Let's return one final time to our original question:

میدانم or میدونم?

Both belong to Persian.

The more useful question is often not simply:

"Which one is correct?"

but:

"Which form would Persian speakers normally use in this context?"

And that's one of the things I want to help you develop as you learn Persian—not only the ability to construct a grammatically understandable sentence, but also the ability to recognize the Persian you read, understand the Persian you hear, and gradually choose the form that fits the situation you're actually in.

So don't panic when the Persian in your textbook and the Persian coming out of your Iranian friend's mouth don't look exactly the same.

You're not suddenly dealing with another language.

You're discovering how Persian actually lives.

Further reading and sources

University of Texas at Austin — Persian Online
The Persian Online project provides teaching materials on differences between formal and informal Persian, including systematic features of colloquial Persian.

Persian Online: What Is Diglossia?

Persian Online: Diglossia — Verb Changes

Cambridge University Press — Bulletin of the School of Oriental and African Studies
For further academic reading on colloquial Persian and its relationship with written Persian:

Notes on the Colloquial Language of Persia as Recorded in Certain Recent Writings — Cambridge University Press