هو قاعد يكتب رسالة على الكمبيوتر.

Yes, the verb يكتب already tells you the subject is he in many contexts. But in Egyptian Arabic, using the pronoun هو is very common and natural.

So:

• يكتب رسالة على الكمبيوتر = He writes / is writing a message on the computer
• هو قاعد يكتب رسالة على الكمبيوتر = more explicit, and often more conversational

Including هو can:

• make the sentence feel more complete
• add emphasis or clarity
• help contrast with someone else

So it is not strictly necessary every time, but it is very normal.

قاعد literally comes from the idea of sitting, but in Egyptian Arabic it is also commonly used to show that someone is in the middle of doing something, especially right now.

So in this sentence:

• هو قاعد يكتب = he is sitting there writing / he is in the process of writing

It often gives a sense similar to the English progressive is writing.

Depending on context, قاعد can:

• literally mean sitting
• or function like a marker of an ongoing action

In this sentence, the second meaning is what matters most.

In Egyptian Arabic, after قاعد, the following verb often comes directly in the imperfect form without بـ:

• قاعد يكتب
• قاعد ياكل
• قاعد يتكلم

This is a very common structure for an action happening right now.

You may also hear بيكتب by itself to mean he is writing in many everyday contexts. But:

• بيكتب often gives a general present or present-progressive sense depending on context
• قاعد يكتب more clearly highlights the ongoing action

So قاعد يكتب is a normal and natural pattern.

This is a very common learner question.

In Egyptian Arabic:

• بيكتب is the usual present-tense form in everyday speech
• bare يكتب often appears after certain words, such as قاعد, عايز, ممكن, and other structures

Compare:

• هو بيكتب رسالة = He writes / He is writing a message
• هو قاعد يكتب رسالة = He is sitting writing a message / He is in the middle of writing a message

So in this sentence, يكتب appears because it follows قاعد.

Yes, قاعد here agrees with the subject.

Since the subject is هو (he), we use قاعد.

Other forms would be:

• هي قاعدة تكتب رسالة على الكمبيوتر = She is writing a message on the computer
• هم قاعدين يكتبوا رسالة على الكمبيوتر = They are writing a message on the computer

So the form changes with gender and number.

رسالة means a message / a letter, while الرسالة means the message / the letter.

So the difference is:

• يكتب رسالة = he is writing a message
• يكتب الرسالة = he is writing the message

If the meaning already shown to the learner is a message, then the indefinite رسالة is exactly what you would expect.

In Egyptian Arabic, indefiniteness is usually shown simply by the absence of الـ.

Yes. على literally means on, and in Arabic it is very natural to say:

• على الكمبيوتر

This often corresponds to English on the computer.

Depending on context, it can mean:

• physically on the computer
• using the computer
• typed on the computer

So this is a normal Arabic way to express the idea.

A simple transliteration is:

huwwa qaʿed yiktib risāla ʿala l-kombyūtar

A more everyday Egyptian-style pronunciation might sound like:

howwa qaʿed yekteb resāla ʿal-kombyūtar

A few pronunciation notes:

• هو is often pronounced howwa or huwwa
• قاعد contains the consonant ع, which does not exist in English
• يكتب is often heard as yekteb in Egyptian pronunciation
• رسالة often sounds like resāla
• على الكمبيوتر becomes smoothly ʿal-kombyūtar

Learners often find ع in قاعد and على the hardest part.

Yes, the word order is very normal.

The sentence is:

• هو = he
• قاعد = in the middle of / sitting and
• يكتب = writes / is writing
• رسالة = a message
• على الكمبيوتر = on the computer

So the overall order is:

subject + ongoing-action marker + verb + object + prepositional phrase

This is very common in Egyptian Arabic.

Arabic can sometimes vary word order, but this sentence is straightforward and natural.

Yes, in many situations you can.

If the subject is already clear from context, Egyptians may say:

• قاعد يكتب رسالة على الكمبيوتر

That can still mean he is writing a message on the computer.

However, including هو is often clearer and more neutral, especially for learners. So both are possible, but هو قاعد يكتب رسالة على الكمبيوتر is a very safe and natural full sentence.

It can mean either, depending on context.

رسالة can refer to:

• a letter
• a message
• a text-like message in some contexts

Because the sentence includes على الكمبيوتر, many learners will understand it as something typed on a computer, so message often feels more natural in context.

If you wanted to be more specific, Arabic could use other expressions depending on the exact kind of message.

Yes. That is one of the useful things about قاعد.

It can give a sense like:

• he is sitting there writing
• he is busy writing
• he is in the middle of writing

English usually just says he is writing, but the Arabic expression can sometimes feel slightly more vivid.

So depending on tone and context, قاعد may add a sense of ongoing involvement in the action, not just bare present tense.

It is clearly natural in Egyptian Arabic.

A few points make it feel Egyptian or colloquial:

• قاعد used this way is common in spoken Arabic varieties
• الكمبيوتر is a modern everyday borrowed word
• the whole sentence is colloquial rather than Formal Arabic

Speakers of other dialects may understand it, but the exact usage and frequency of قاعد can vary from one dialect to another. In Egyptian Arabic, this sentence sounds normal and conversational.