أنا أنظف الطاولة، وأختي ترتب الكراسي عند المائدة.

A careful MSA reading is:

أنا أُنَظِّفُ الطاولةَ، وأختي تُرَتِّبُ الكراسيَ عندَ المائدةِ.

A few useful pronunciation notes:

• أُنَظِّفُ = I clean
• تُرَتِّبُ = she arranges
• أختي is pronounced roughly ukhtī
• In الطاولة, the ال assimilates to ط because ط is a sun letter, so it sounds like aṭ-ṭāwila

In normal Arabic writing, short vowels and shadda are usually not written, so learners often see the simpler form: أنا أنظف الطاولة، وأختي ترتب الكراسي عند المائدة.

Because Arabic verbs already show the subject, أنا is not strictly necessary.

So:

• أنا أنظف الطاولة = I clean the table
• أنظف الطاولة = also I clean the table

Using أنا can add clarity, emphasis, or contrast. In a sentence with two different people, it can help highlight the contrast: I do one thing, and my sister does another.

Because the verb ترتب already shows she here.

In the present tense, تـ can mark several forms, but in this sentence the subject أختي makes it clear that it means she arranges.

So وأختي ترتب الكراسي literally works like:

• and my sister arranges the chairs

You do not need هي before the verb unless you want extra emphasis or a slightly different structure.

It is part of the present-tense conjugation.

The verb رتّب means to arrange / to put in order. In the present tense:

• أرتب = I arrange
• ترتب = she arranges or you arrange (depending on context)

Here, because the subject is أختي (my sister), ترتب must mean she arranges.

The -ي is a possessive suffix meaning my.

So:

• أخت = sister
• أختي = my sister

This is a very common Arabic pattern:

• أخي = my brother
• كتابي = my book
• بيتي = my house

Because a noun with a possessive suffix is already definite.

So:

• أخت = a sister / sister
• الأخت = the sister
• أختي = my sister

You would not say الأختي. The suffix -ي already makes it definite.

ال is the Arabic definite article, meaning the.

So:

• الطاولة = the table
• الكراسي = the chairs
• المائدة = the table / the dining table

Arabic uses ال when the noun is specific or understood from context, just like English uses the.

Yes, they can overlap, but there is a nuance.

• طاولة is a general word for table
• مائدة often means a dining table or a table set for food

So in this sentence:

• الطاولة may sound like the physical table being cleaned
• المائدة suggests the dining area/table where the chairs are arranged

In many everyday contexts, they may both be translated as table, but مائدة often has a more dining-related sense.

Here عند means something like at, by, or near.

So:

• عند المائدة = at the table / by the table

It does not mean on the table. If Arabic wanted to say on the table, it would usually use على:

• على المائدة = on the table

Because Arabic has many broken plurals, where the inside of the word changes instead of just adding a regular ending.

Here:

• كرسي = chair
• كراسي = chairs

This is a very common feature of Arabic. English speakers often expect one regular plural pattern, but Arabic has several. It is best to learn many nouns together with their plural forms.

Because و is a short connecting word, a clitic, and in Arabic it is written attached to the following word.

So:

• و = and
• وأختي = and my sister

This is normal Arabic spelling. You will see the same thing with other short particles too.

This is a very good question, because unvowelled Arabic writing can be ambiguous.

The spelling أنظف can represent different words depending on the vowels:

• أُنَظِّفُ = I clean (verb)
• أَنْظَفُ = cleaner / cleanest (adjective/comparative)

In this sentence, the context after أنا makes it clear that it is the verb I clean.

It can mean either one.

In Arabic, the present tense often covers both:

• I clean
• I am cleaning

So:

• أنا أنظف الطاولة can mean I clean the table or I am cleaning the table

Context tells you which meaning is intended. If you want to make the ongoing action clearer, you can add a word like الآن:

• أنا أنظف الطاولة الآن = I am cleaning the table now

Yes, to some extent.

For the first clause:

• أنا أنظف الطاولة = I clean the table
• أنظف الطاولة = also I clean the table

For the second clause, Arabic can also allow different word orders, such as a more verb-first style:

• وأختي ترتب الكراسي عند المائدة
• وترتب أختي الكراسي عند المائدة

Both are possible, though the emphasis can feel slightly different.

If you omit أختي, then the sentence would just mean and she arranges the chairs at the table, so you would lose the explicit meaning my sister unless the context already makes it clear.