من امروز صبح در اتاقم پشت میز نشستم و با کامپیوتر کار کردم.

You can usually leave it out.

In Persian, the verb ending already shows the subject:

• نشستم = I sat
• کار کردم = I worked

So this sentence could naturally be:

امروز صبح در اتاقم پشت میز نشستم و با کامپیوتر کار کردم.

Adding من is not wrong. It just makes the subject more explicit, and it may add a little emphasis, like I did this.

Yes, literally it is something like today morning, but in natural English it means this morning.

• امروز = today
• صبح = morning

So امروز صبح is a very common way to say this morning.

You may also see صبح امروز, which also refers to this morning, but امروز صبح is very common in everyday speech.

This is the noun اتاق plus the attached ending -م, which means my.

• اتاق = room
• اتاقم = my room

This attached ending is very common in Persian:

• کتابم = my book
• دوستم = my friend
• خانه‌ام / خونم = my house/home

So در اتاقم means in my room.

در here means in.

• در اتاقم = in my room

Yes, in everyday spoken Persian, تو اتاقم is also very common and natural.

Roughly speaking:

• در = a bit more neutral, standard, or slightly more formal
• تو = very common in speech

So both work, but در اتاقم is perfectly natural.

Yes, literally پشت میز means behind the desk/table.

But in context, especially with sitting and working, it often corresponds to natural English at the desk or sitting at the desk.

So:

• پشت میز نشستم literally = I sat behind the desk
• natural English sense = I sat at the desk

This is a good example where Persian and English describe the same situation a little differently.

Yes. It is pronounced پشتِ میز, with an -e sound linking the two words.

However, that short vowel is usually not written in normal Persian spelling, so you see:

پشت میز

but you pronounce it like:

posht-e miz

This linking sound is very common in Persian. English speakers often need time to get used to the fact that it is heard but often not written.

نشستم is the simple past of نشستن, meaning to sit or to sit down.

It breaks down like this:

• infinitive: نشستن
• past stem: نشست-
• -م = I

So:

• نشستم = I sat / I sat down

In this sentence, نشستم describes a completed action in the past.

Because کار کردن is a compound verb, and Persian uses these very often.

• کار = work
• کردن = to do

Together:

• کار کردن = to work

In the past tense, only کردن gets conjugated:

• کار کردم = I worked
• کار کردی = you worked
• کار کرد = he/she worked

This pattern is extremely common in Persian, so it is worth getting comfortable with compound verbs early.

Yes, با usually means with, and here it shows the instrument or tool you used.

So:

• با کامپیوتر کار کردم = I worked with the computer

In natural English, depending on context, you might translate that as:

• I worked on the computer
• I worked with a computer

Both are possible, even though Persian uses با.

Because Persian is generally a subject-object-verb language, and verbs often come near the end.

The sentence structure is roughly:

• من = I
• امروز صبح = this morning
• در اتاقم = in my room
• پشت میز = at/behind the desk
• نشستم = sat
• و = and
• با کامپیوتر = with/on the computer
• کار کردم = worked

So Persian often puts time and place information before the verb. This is very normal.

Yes, very natural.

A Persian speaker would often say:

امروز صبح در اتاقم پشت میز نشستم و با کامپیوتر کار کردم.

Because the endings on نشستم and کردم already show I, the pronoun is not necessary unless you want emphasis or contrast.

For example:

• من امروز صبح... = I this morning...
  • maybe contrasting with someone else

Without من, it sounds smooth and normal.

Yes. Both نشستم and کار کردم are in the simple past.

That means the sentence describes two completed past actions:

1. I sat down / sat at the desk
2. I worked on the computer

Using و links the two actions together in a straightforward narrative way.

It can mean both, depending on context.

• میز = table / desk

In this sentence, because the speaker is sitting and working on a computer, English would usually translate it as desk.

So:

• پشت میز نشستم here is best understood as I sat at my desk or I sat at the desk

Context tells you which English word fits best.