الشركة في العمارة الكبيرة.

A natural Egyptian pronunciation would be:

esh-sherka fi l-ʿamāra l-kebīra

A rough English-style guide:

• esh-sherka = the company
• fi = in
• l-ʿamāra = the building
• l-kebīra = the big one / the big

A few notes:

• In الشركة, the ال becomes esh- because ش is a “sun letter,” so the l sound assimilates.
• In fast speech, في العمارة often sounds like fil-ʿamāra.
• The ع in العمارة is a consonant English does not have, so learners often need extra practice with it.

Because Arabic often leaves out is/are in present-tense sentences like this.

So:

• الشركة في العمارة الكبيرة literally looks like the company in the big building
• but it means The company is in the big building

This is completely normal in both Standard Arabic and Egyptian Arabic.
If you want past or future, then you usually need extra words:

• كانت الشركة في العمارة الكبيرة = The company was in the big building
• هتكون الشركة في العمارة الكبيرة = The company will be in the big building

In Egyptian Arabic, عمارة usually means a building, and very often specifically an apartment building or multi-story residential building.

So في العمارة الكبيرة usually suggests:

• in the big building
• possibly in the large apartment building

Depending on context, Egyptians might use:

• مبنى for a building in a more formal or general sense
• عمارة for the kind of building people live in or recognize as a street building/block

So this sentence sounds very natural if you are talking about an office or company located inside a certain building.

Because in Arabic, adjectives normally come after the noun they describe.

So:

• العمارة الكبيرة = literally the building the-big
• natural English translation: the big building

This is the normal word order in Arabic:

• بيت كبير = a big house
• البنت الجميلة = the beautiful girl
• العربية الجديدة = the new car

Because when an adjective describes a definite noun, the adjective must also be definite.

Here:

• العمارة = the building
• so the adjective must also be definite:
• الكبيرة = the big

That is why you get:

• العمارة الكبيرة = the big building

Compare:

• عمارة كبيرة = a big building
• العمارة الكبيرة = the big building

If you said العمارة كبيرة, that would usually mean:

• The building is big

So the presence or absence of ال changes the structure and meaning.

Because العمارة is a feminine noun, and adjectives must agree with the noun.

So:

• عمارة = feminine
• therefore the adjective is feminine too:
• كبيرة = big (feminine)

Compare:

• مبنى كبير = a big building
• عمارة كبيرة = a big building

Even though both can translate as building, the grammatical gender of the Arabic noun matters.

It works in Egyptian Arabic, but it is also very close to Standard Arabic in wording.

An Egyptian speaker could absolutely say:

• الشركة في العمارة الكبيرة

In everyday speech, though, Egyptians might also say similar things like:

• الشركة في العمارة الكبيرة دي = The company is in this big building
• الشركة جوه العمارة الكبيرة = The company is inside the big building
• مقر الشركة في العمارة الكبيرة = The company headquarters is in the big building

So your sentence is natural and understandable, though a real spoken context might add words like دي or جوه.

في is the preposition meaning in.

So:

• الشركة = the company
• في = in
• العمارة الكبيرة = the big building

Together:

• الشركة في العمارة الكبيرة = The company is in the big building

This is one of the most common Arabic prepositions. You will see it in many everyday sentences:

• أنا في البيت = I’m at home
• هي في الشغل = She is at work
• الكتاب في الشنطة = The book is in the bag

Usually الشركة means the company, not the office.

However, in real life, people sometimes use company in a practical sense to refer to the place where the company is located, especially in context. So depending on the situation, an English translation might end up sounding like:

• The company is in the big building
• or more naturally in context: The office is in the big building

But the Arabic word itself is still company.
If you specifically want office, you might use:

• مكتب = office
• مقر الشركة = company headquarters / company office

Most directly, في means in, so the sentence suggests the company is in the building.

In real usage, though, prepositions can be a little flexible, just like in English. Depending on context, it could imply:

• located inside the building
• based in that building
• at that building address

If you want to be more explicitly physical about being inside, Egyptian Arabic often uses:

• جوه = inside

So:

• الشركة في العمارة الكبيرة = The company is in the big building
• الشركة جوه العمارة الكبيرة = The company is inside the big building

Yes. There are three words with ال:

• الشركة
• العمارة
• الكبيرة

But they are not all pronounced the same way.

1. الشركة

   • ش is a sun letter
   • so ال assimilates
   • pronounced esh-sherka, not el-sherka

2. العمارة

   • ع is a moon letter
   • so the l is pronounced
   • el-ʿamāra

3. الكبيرة

   • ك is also a moon letter
   • so again the l is pronounced
   • el-kebīra

This is a very common thing learners need to notice when reading Arabic aloud.

You would remove the definiteness:

• شركة في عمارة كبيرة

That means:

• a company in a big building
• or in full English: A company is in a big building

Compare carefully:

• الشركة في العمارة الكبيرة = The company is in the big building
• شركة في عمارة كبيرة = A company is in a big building

Arabic marks definiteness very clearly, and that affects both nouns and adjectives.