اگر او را در دانشگاه دیدی، به من پیام بده.

را is the direct object marker in Persian. It marks the noun or pronoun that receives the action.

So in:

اگر او را در دانشگاه دیدی...

او را means him/her as the object of دیدی (you saw / you see in this conditional structure).

A few helpful points:

• او = he / she
• او را = him / her
• In spoken Persian, this is often shortened:
  • او را → اونو or او رو

So a more conversational version might be:

اگر اونو در دانشگاه دیدی...

or

اگه اونو توی دانشگاه دیدی...

It can mean either. Persian third-person singular pronouns are not gendered.

So:

• او = he / she
• او را = him / her

You only know the gender from context, not from the pronoun itself.

This is true for most ordinary Persian pronouns:

• من = I
• تو = you
• او = he/she

Yes, دیدی is formally the simple past, second person singular of دیدن (to see):

• دیدم = I saw
• دیدی = you saw
• دید = he/she saw

But in Persian, especially in if-clauses, the simple past can be used where English uses the present:

• اگر او را دیدی، ... = If you see him/her, ...

So even though it looks like you saw, the actual meaning in this sentence is if you happen to see him/her.

This is very common and natural in Persian.

A more explicitly non-past version is also possible:

• اگر او را ببینی، به من پیام بده.

That also means If you see him/her, message me.

Very roughly:

• اگر ... دیدی = very common, natural
• اگر ... ببینی = also correct, often felt a bit more explicitly tied to a future possibility

دیدی comes from the verb دیدن (to see).

Its past stem is:

• دید-

Then Persian adds personal endings. For you singular in the simple past, the ending is:

• -ی

So:

• دید + ی = دیدی

That gives you saw / in this sentence’s structure, if you see.

Persian usually follows subject–object–verb order, and the verb normally comes at the end.

In this sentence:

اگر او را در دانشگاه دیدی، به من پیام بده.

the order is roughly:

• اگر = if
• او را = him/her
• در دانشگاه = at the university
• دیدی = you saw / you see
• به من = to me
• پیام بده = send a message

So Persian tends to place:

• objects before the verb
• location phrases before the verb
• the main verb at the end of the clause

That is why دیدی and بده both come late.

در دانشگاه means at the university or in the university.

• در = in / at
• دانشگاه = university

In everyday spoken Persian, learners will often hear:

• توی دانشگاه
• تو دانشگاه

These are more conversational than در دانشگاه.

So these are all possible, depending on style:

• در دانشگاه → more neutral/written
• توی دانشگاه → common spoken
• تو دانشگاه → very common spoken

Literally, پیام بده means give a message, but in natural English it means:

• send me a message
• message me
• text me

This is a very common Persian pattern: a noun plus دادن (to give) forms a compound verb.

Here:

• پیام = message
• بده = give! (imperative of دادن)

Together:

• پیام بده = message/send a message

Because the sentence already includes به من (to me), the full meaning is:

• message me
• send me a message

Because من is I / me, but Persian usually marks the receiver of something with به (to).

So:

• به من = to me
• به او = to him/her
• به ما = to us

With پیام دادن (to send a message / message someone), the person receiving the message is commonly introduced by به:

• به من پیام بده = send me a message
• بهش پیام بده = send him/her a message

In spoken Persian, به من often becomes:

• بهم

So a common spoken version is:

• بهم پیام بده

بده is the imperative form of دادن (to give) for you singular.

So it means:

• give!
• and here, as part of the compound verb, message! / send a message!

This form is used when speaking to one person informally.

Compare:

• بده = give! / message! (informal singular)
• بدهید = give! / message! (formal singular or plural)

So this sentence is addressing one person informally.

To make it formal, the most obvious change is the command:

• پیام بده → پیام بدهید

So the formal version would be:

اگر او را در دانشگاه دیدید، به من پیام بدهید.

Changes:

• دیدی → دیدید = if you see/saw (formal or plural you)
• بده → بدهید = message/send a message (formal or plural)

If you are speaking respectfully to one person, this is the version you would normally use.

It is somewhere in the middle, but it leans a bit more toward neutral/written because of forms like:

• اگر instead of اگه
• او را instead of اونو / او رو
• در دانشگاه instead of تو/توی دانشگاه

At the same time, دیدی and پیام بده are perfectly natural and common.

A more conversational spoken version would be:

اگه اونو توی دانشگاه دیدی، بهم پیام بده.

This means the same thing, but sounds more everyday and spoken.

Yes. You can also say:

اگر او را در دانشگاه ببینی، به من پیام بده.

This is also correct and natural.

The difference is subtle for many learners:

• اگر ... دیدی is very common in everyday Persian
• اگر ... ببینی uses the subjunctive/present stem pattern and also clearly expresses a future possibility

In many real contexts, both are acceptable and mean essentially the same thing:

• If you see him/her at the university, message me.

As a learner, you should understand both.

They both mean if.

• اگر = standard, more careful, more written
• اگه = spoken, colloquial

So:

• اگر او را در دانشگاه دیدی...
• اگه اونو تو دانشگاه دیدی...

Both are fine, but the second sounds more conversational.

The comma separates the if-clause from the main command:

• اگر او را در دانشگاه دیدی، = If you see him/her at the university,
• به من پیام بده. = message me.

This is similar to English punctuation in sentences like:

• If you see her, text me.

In Persian writing, commas are commonly used this way, especially in clear written style.

It is broader than just text me.

Depending on context, به من پیام بده can mean:

• text me
• message me
• send me a message

If the context is mobile phones or chat apps, it often naturally means text/message me.

If you want to be more specific, Persian can also use expressions like:

• اس‌ام‌اس بده = send an SMS
• پیامک بده = send a text message
• مسج بده = message (colloquial, borrowed style)

But پیام بده is very common and natural.

A very natural spoken version would be:

اگه اونو توی دانشگاه دیدی، بهم پیام بده.

Changes from the original:

• اگر → اگه
• او را → اونو
• در دانشگاه → توی دانشگاه
• به من → بهم

All of these are common spoken reductions. The meaning stays the same.

Yes, often it can.

Because the verb form already shows the person, Persian frequently omits subjects and sometimes uses less explicit objects if context is clear.

But in this sentence, او را is useful because it clearly tells you who should be seen.

If context already makes the person obvious, a speaker might say something shorter like:

• اگر دیدیش، بهم پیام بده.

This means:

• If you see him/her, message me.

Here -ش means him/her, attached to the verb.

That is a very common spoken structure.