وقتی تو به من پیام فرستادی، من داشتم در حمام دوش میگرفتم.

وقتی means when. It introduces the time clause:

وقتی تو به من پیام فرستادی
= when you sent me a message

So the whole sentence is structured like:

When X happened, I was doing Y.

This is a very common way to connect two past actions in Persian.

Yes, they are often optional because the verb endings already show the subject.

So this sentence could also be said as:

وقتی به من پیام فرستادی، داشتم در حمام دوش می‌گرفتم.

That would still be completely clear.

Including تو and من can add emphasis or make the sentence feel a little more explicit. In everyday Persian, speakers often leave them out unless they want contrast or emphasis.

به من means to me.

• به = to
• من = me

In casual spoken Persian, this often becomes:

بهم

So a very natural spoken version would be:

وقتی بهم پیام فرستادی، داشتم در حمام دوش می‌گرفتم.

Both are correct. به من is a bit fuller and clearer; بهم is very common in speech.

Persian often uses verb phrases where English uses a single verb.

Here:

• پیام = message
• فرستادی = you sent

So literally it is you sent a message to me.

This is a very normal Persian way to express you messaged me. You may also hear:

• پیام دادی = you gave/sent a message
• برام پیام فرستادی = you sent me a message

All of these are natural, with slightly different style or register.

Because پیام here is nonspecific, more like a message rather than the message.

In Persian, را usually marks a specific direct object. So:

• پیام فرستادی = you sent a message / messaged
• پیام را فرستادی = you sent the message

In this sentence, the speaker just means you sent me a message, not a particular already-known message, so no را is needed.

فرستادی is the simple past, second person singular, from فرستادن = to send.

Breakdown:

• verb stem: فرستاد-
• ending -ی = you (singular, informal)

So:

• فرستادم = I sent
• فرستادی = you sent
• فرستاد = he/she sent
• فرستادیم = we sent
• فرستادید = you sent (plural or formal)
• فرستادند = they sent

Because the sentence uses تو, it is informal singular you.

This is a common way to make the past progressive in Persian.

• داشتم = I was having / I had
• می‌گرفتم = I was taking / I used to take

Together, they mean:

I was in the middle of taking

So:

داشتم دوش می‌گرفتم
= I was taking a shower

This structure often shows an action that was ongoing when another past action happened.

That fits perfectly with the first clause:

When you sent me a message, I was taking a shower.

Yes, you could say:

وقتی تو به من پیام فرستادی، در حمام دوش می‌گرفتم.

This can still be understood, but داشتم makes the progressive meaning clearer and stronger. It emphasizes that the action was ongoing at that moment.

So:

• می‌گرفتم alone can sometimes mean I was taking or I used to take, depending on context.
• داشتم می‌گرفتم clearly means I was taking at that time.

That is why داشتم is very useful here.

Literally, it means I was taking a shower.

This is built from:

• دوش = shower
• گرفتن = to take

So Persian, like English, uses a light verb construction here:

دوش گرفتن = to take a shower

This is very common in Persian. Many actions are expressed with a noun + a general verb such as کردن, زدن, or گرفتن.

Because Persian often allows extra location information even if it seems obvious.

• در حمام = in the bathroom
• دوش می‌گرفتم = I was taking a shower

So the sentence is a bit like:

I was taking a shower in the bathroom.

In English, that may feel slightly redundant, but in Persian it is not strange. Still, many speakers would simply say:

داشتم دوش می‌گرفتم.

That is already enough in most situations.

It is correct, but there are other very natural options.

For example:

• داشتم حمام می‌کردم = I was bathing / showering
• داشتم دوش می‌گرفتم = I was taking a shower
• توی حموم داشتم دوش می‌گرفتم = I was taking a shower in the bathroom (more conversational)

A spoken version might be:

وقتی بهم پیام فرستادی، داشتم توی حموم دوش می‌گرفتم.

So the original sentence is fine, but slightly more neutral or careful in style.

They mean roughly the same thing here, but the style is different.

• در حمام = more neutral, standard, slightly more formal
• توی حموم = more conversational and spoken

Also note the pronunciation difference:

• حمام is the standard written form
• حموم is a very common spoken form

So if you are writing carefully, در حمام is a good choice. If you are speaking casually, توی حموم sounds very natural.

Yes, in standard Persian spelling it is usually written:

می‌گرفتم

with a small invisible separator called a zero-width non-joiner between می and the verb.

So the standard form is:

• می‌گرفتم

But many people type it without that separator:

• میگرفتم

Both are understood, but می‌گرفتم is the more standard written form.

The same applies to many verbs:

• می‌روم
• می‌کنم
• می‌نویسم

Yes. Persian is flexible here.

You can say:

من داشتم در حمام دوش می‌گرفتم وقتی تو به من پیام فرستادی.

This is understandable, but the version with وقتی first is often smoother and more natural:

وقتی تو به من پیام فرستادی، من داشتم در حمام دوش می‌گرفتم.

Putting the when clause first is especially common when setting the scene before the main action.

Yes. تو is singular informal you.

If you wanted to say it politely or formally, you would use شما and change the verb:

وقتی شما به من پیام فرستادید، من داشتم در حمام دوش می‌گرفتم.

So:

• تو ... فرستادی = informal singular
• شما ... فرستادید = formal or plural

Everything else in the sentence can stay basically the same.

It shows a very common pattern:

• one shorter completed past action
• one longer ongoing past action

In this sentence:

• تو به من پیام فرستادی = completed event
• من داشتم در حمام دوش می‌گرفتم = ongoing background action

So the meaning is:

Your message happened during my shower.

This is one of the most useful past-time patterns in Persian, and it works much like English:

When you texted me, I was taking a shower.