عندما أعود من العمل، أجلس على الكرسي قرب النافذة.

Because the verb already tells you the subject.

• أعود means I return / I come back
• أجلس means I sit

The prefix أ- on these present-tense verbs marks first person singular, so أنا is not necessary.

You could say:

• عندما أنا أعود... ❌ unnatural
• عندما أعود... ✅ natural

If you want extra emphasis, you can add أنا, but normally Arabic leaves it out because the verb already includes the subject.

عندما means when.

In this sentence, it introduces a time clause:

• عندما أعود من العمل = when I return from work

Then the main action follows:

• أجلس على الكرسي قرب النافذة = I sit on the chair near the window

So the whole structure is:

• عندما + verb/clause, main clause
• When + clause, main clause

It is a very common way to connect two actions in Modern Standard Arabic.

In Arabic, the present tense can express habitual actions, not just something happening right now.

So this sentence means something like:

• Whenever I come back from work, I sit on the chair near the window
• or When I return from work, I sit on the chair near the window

The present tense here describes a routine or repeated behavior.

That is why Arabic uses:

• أعود = I return / I come back
• أجلس = I sit

even though in English the meaning may feel habitual or general.

Yes, أعود comes from the verb عاد and means:

• I return
• I come back
• sometimes I go back, depending on context

In this sentence, أعود من العمل most naturally means:

• I return from work
• I come back from work

For an English speaker, come back often feels especially natural here.

Because من is the preposition meaning from.

So:

• من العمل = from work

Word by word:

• من = from
• العمل = the work

Arabic often uses the in places where English does not. So even though English usually says from work, Arabic says from the work literally.

This is normal and very common.

Arabic uses the definite article الـ in many places where English uses no article.

So:

• العمل literally = the work
• but in natural English translation here = work

This is not unusual. Arabic and English do not use articles in exactly the same way.

Compare:

• أنا في البيت = literally I am in the house, but often simply I am at home
• أذهب إلى المدرسة = literally I go to the school, but often just I go to school

So من العمل is the normal Arabic way to say from work.

على means on.

So:

• أجلس على الكرسي = I sit on the chair

This is the normal Arabic preposition with sit in this kind of sentence.

Word by word:

• أجلس = I sit
• على = on
• الكرسي = the chair

English speakers sometimes wonder whether Arabic might use something like in here, but with a chair, على is the expected choice.

قرب النافذة means near the window.

Word by word:

• قرب = near / close to
• النافذة = the window

So:

• على الكرسي قرب النافذة = on the chair near the window

In this sentence, قرب النافذة tells you the location of the chair.

It behaves a lot like a preposition in sentences like this, but grammatically it is often treated as a noun/adverbial expression of place.

For a learner, the most useful thing is:

• قرب + noun = near + noun

Examples:

• قرب البيت = near the house
• قرب المدرسة = near the school
• قرب النافذة = near the window

So even if its grammatical label is a little more complex, you can safely learn it as meaning near in this pattern.

Because the sentence refers to specific things:

• الكرسي = the chair
• النافذة = the window

Arabic often uses definiteness clearly and consistently. In this sentence, the speaker is not talking about just any chair or any window, but a particular chair and a particular window.

So:

• أجلس على كرسي قرب نافذة would mean I sit on a chair near a window
• أجلس على الكرسي قرب النافذة means I sit on the chair near the window

The second version sounds more specific.

Yes. Arabic word order is flexible.

The given sentence:

• عندما أعود من العمل، أجلس على الكرسي قرب النافذة.

is completely natural.

You could also start with the main clause in some contexts, but this version is especially clear because it sets the time first:

• When I come back from work, I sit...

Putting the when clause first is common and natural in both Arabic and English.

Not in the same strict way as in English.

In modern printed Arabic, a comma is often used after an opening clause like this:

• عندما أعود من العمل، أجلس...

So the punctuation here is normal and helpful.

However, Arabic punctuation is sometimes less rigid than English punctuation, especially in informal writing. The sentence would still be understandable without the comma.

A fully vowelled version would be:

عِندَما أَعودُ مِنَ العَمَلِ، أَجلِسُ عَلَى الكُرسِيِّ قُربَ النّافِذَةِ.

This shows the grammatical endings more clearly.

A few useful points:

• أعودُ ends in -u because it is a present-tense verb in normal indicative form
• مِنَ العَمَلِ: after the preposition من, العمل is in the genitive
• عَلَى الكُرسِيِّ: after على, الكرسي is also genitive
• قُربَ النّافِذَةِ: قرب is commonly pronounced with -a here, and النافذةِ is genitive after it

In everyday unvowelled Arabic writing, these endings are usually omitted.

A simple learner-friendly pronunciation is:

• الكرسي = al-kursiyy
• النافذة = an-naafidhah

A few details:

• In النافذة, the ل of الـ is not pronounced normally because ن is a sun letter
• So النافذة sounds like an-naafidhah, not al-naafidhah

By contrast:

• الكرسي keeps the l sound because ك is a moon letter
• so it is al-kursiyy

This sun-letter/moon-letter pattern is a very common feature of Arabic pronunciation.

Yes, often you can.

For example:

• حين أعود من العمل، أجلس على الكرسي قرب النافذة.

also means roughly:

• When I return from work, I sit on the chair near the window.

However, عندما is very common in Modern Standard Arabic and is a very safe choice for learners.

So while both may work, the original sentence with عندما is completely natural and standard.

Arabic أجلس can cover the idea of I sit and, depending on context, sometimes the act of sitting down as well.

In English, we often distinguish:

• I sit = state/habit
• I sit down = action of moving into the seated position

Arabic does not always make that distinction in the same way. In this sentence, أجلس naturally expresses the idea intended by the full sentence.

If the context is habitual, English may translate it simply as:

• I sit on the chair near the window

That is the most natural basic understanding here.

Yes, very easily.

Because of:

• عندما = when
• present tense verbs = habitual or repeated action in this context

the sentence naturally suggests a routine:

• Whenever I return from work, I sit on the chair near the window

So even if the English translation shown to the learner is just When I return from work, I sit on the chair near the window, the Arabic can strongly suggest a repeated habit.

A common way to negate the present-tense actions in Modern Standard Arabic is with لا.

For example:

• عندما أعود من العمل، لا أجلس على الكرسي قرب النافذة.
• When I return from work, I do not sit on the chair near the window.

If you want to negate the first clause instead:

• عندما لا أعود من العمل... is possible in some contexts, but usually the meaning needs careful context

For a learner, the simplest useful pattern is:

• أجلس = I sit
• لا أجلس = I do not sit

A good way to learn it is in meaningful pieces:

• عندما أعود = when I return / when I come back
• من العمل = from work
• أجلس على الكرسي = I sit on the chair
• قرب النافذة = near the window

This helps you reuse the patterns:

• عندما أصل إلى البيت... = when I arrive home...
• من المدرسة = from school
• أجلس على السرير = I sit on the bed
• قرب الباب = near the door

Learning chunks is often more useful than memorizing single isolated words.