أجلس على الكرسي عند الطاولة وأكتب في دفتري بالقلم الأزرق.

In Arabic, the verb itself already shows the subject. أجلس means I sit / I am sitting, so أنا is not necessary.

You can add أنا if you want emphasis or contrast:

• أنا أجلس وأنت تكتب = I am sitting, and you are writing

But in a normal neutral sentence, just أجلس is perfectly natural.

Both are in the imperfect form, which is often called the present tense in beginner Arabic.

Depending on context, this form can mean:

• I sit / I write
• I am sitting / I am writing
• sometimes even I usually sit / I usually write

So Arabic does not always separate simple present and present continuous the way English does. Context tells you which meaning is intended.

Each one has a different job:

• على الكرسي = on the chair
• عند الطاولة = at / by the table
• في دفتري = in my notebook
• بالقلم الأزرق = with the blue pen

Arabic uses prepositions very specifically, and they do not always match English one-for-one. So it is best to learn them as part of whole expressions, such as:

• جلس على = sit on
• عند الطاولة = at the table
• كتب في دفتره = write in his notebook
• كتب بالقلم = write with the pen

عند often means at, by, near, or in the presence of, depending on context.

In this sentence, عند الطاولة means the person is positioned by the table or at the table, not literally on top of it.

If you said على الطاولة, that would usually mean on the table, physically on its surface. So:

• عند الطاولة = at the table
• على الطاولة = on the table

The prefix الـ means the.

So:

• الكرسي = the chair
• الطاولة = the table

Arabic often uses definite nouns when talking about a specific, known object in the scene. This is similar to English the chair and the table.

Without الـ, the meaning would become more like:

• كرسي = a chair
• طاولة = a table

دفتري means my notebook.

It is made from:

• دفتر = notebook
• ـي = my

So:

• دفتر = notebook
• دفتري = my notebook

When a noun has a possessive suffix like ـي, it is already definite, so you do not add الـ.

That is why my notebook is:

• دفتري

  not:

• الدفتري

In Arabic, أكتب في دفتري is a very natural way to say I write in my notebook.

The idea is that the writing is going into the notebook, onto its pages, so في is idiomatic here.

English often says write in a notebook, and Arabic does too:

• أكتب في دفتري = I write in my notebook

In some other contexts, Arabic can use على for writing on a surface, such as:

• أكتب على الورقة = I write on the paper

So the choice depends partly on the type of object and common usage.

The preposition بـ often means with, especially for instruments or tools.

So:

• بالقلم = with the pen / using the pen

In this sentence, بالقلم الأزرق means with the blue pen or using the blue pen.

This is a very common Arabic pattern:

• أكتب بالقلم = I write with the pen
• قطع بالسكين = he cut with the knife

In Arabic, adjectives usually come after the noun they describe.

So:

• القلم الأزرق = the blue pen

not the English order blue pen.

Arabic adjective order is:

• noun first
• adjective second

Examples:

• البيت الكبير = the big house
• الكتاب الجديد = the new book
• القلم الأزرق = the blue pen

Both are possible, but they mean slightly different things.

• القلم الأزرق = the blue pen
• قلم أزرق = a blue pen

The sentence uses the definite form, so it sounds like a specific blue pen is meant.

Also, when the noun is definite, the adjective must also be definite:

• القلم الأزرق = the blue pen

When the noun is indefinite, the adjective is also indefinite:

• قلم أزرق = a blue pen

This matching is very important in Arabic.

Yes. Arabic adjectives agree with the noun they describe in several ways, including:

• gender
• number
• definiteness
• case in fully vocalized Arabic

Here:

• القلم is masculine singular definite
• الأزرق is also masculine singular definite

So they match correctly.

If the noun were feminine, the adjective would change too. For example:

• الطاولة الزرقاء = the blue table

و means and.

So:

• أجلس ... وأكتب ... = I sit ... and I write ...

It simply connects the two actions.

When attached to the next word, Arabic writes it as one unit:

• و + أكتب = وأكتب

This is very normal in Arabic spelling.

Arabic word order is fairly flexible, especially with phrases like على الكرسي, عند الطاولة, في دفتري, and بالقلم الأزرق.

The given sentence is natural:

• أجلس على الكرسي عند الطاولة وأكتب في دفتري بالقلم الأزرق

But other orders are also possible, depending on emphasis. For example:

• أجلس عند الطاولة على الكرسي
• وأكتب بالقلم الأزرق في دفتري

These alternatives are possible, but the original order is clear and smooth for a learner.

Yes. In fully vocalized formal Arabic, there would be case endings, but in normal everyday writing they are usually omitted.

A fully vocalized version could look like this:

• أجلسُ على الكرسيِّ عندَ الطاولةِ وأكتبُ في دفتري بالقلمِ الأزرقِ

Here is why:

• أجلسُ and أكتبُ end in ـُ because they are present-tense verbs in a normal indicative form
• nouns after prepositions like على, في, and بـ are in the genitive
• الطاولةِ is also genitive after عند in this structure

Beginners usually read and write these sentences without the endings, which is completely normal in most Arabic texts.