الشارع ده طويل.

In Egyptian Arabic, the common pattern is:

noun + demonstrative

So الشارع ده literally looks like the street this, but it means this street.

This is very normal in Egyptian Arabic.
Compare:

• الولد ده = this boy
• البيت ده = this house
• البنت دي = this girl

This is different from English, where this comes before the noun.

In the present tense, Arabic usually does not use a separate word for is/am/are.

So:

• الشارع ده طويل = This street is long

There is no spoken equivalent of is here, but the meaning is still complete and natural.

This is very common in both Egyptian Arabic and Standard Arabic for simple present-tense sentences.

Because طويل here is the predicate of the sentence, not part of a noun phrase like the long street.

Compare these two:

• الشارع الطويل = the long street
  Here, طويل is directly describing the noun inside one phrase, so it takes ال: الطويل.

• الشارع ده طويل = this street is long
  Here, طويل comes after the subject and acts like is long, so it does not take ال.

So the lack of ال helps show that this is a full sentence, not just a noun phrase.

A natural Egyptian pronunciation is approximately:

esh-shāreʿ da ṭawīl

A few helpful notes:

• الشارع is often pronounced esh-shāreʿ, not al-shāreʿ
• this happens because ش is a sun letter, so the l in ال assimilates
• ده is usually pronounced da or deh, depending on speaker and style
• طويل is roughly ṭa-weel, with a heavy ṭ

So the whole sentence sounds like:

esh-shāreʿ da ṭawīl

Here, ده is the masculine singular demonstrative, meaning this.

It changes depending on gender and number:

• ده = masculine singular
• دي = feminine singular
• دول = plural

Examples:

• الشارع ده = this street
• العربية دي = this car
• الكتب دول = these books

Since شارع is masculine singular, ده is the correct form here.

Because it agrees with الشارع, which is a masculine singular noun.

In Arabic, adjectives usually agree with the noun in:

• gender
• number
• definiteness, when they are directly attributive

Here, طويل is masculine singular because شارع is masculine singular.

If the noun were feminine, the adjective would change:

• العربية دي طويلة = This car is long

So:

• masculine: طويل
• feminine: طويلة

This is Egyptian Arabic.

The clearest sign is ده after the noun. In Modern Standard Arabic, you would normally say:

هذا الشارع طويل

Both mean This street is long, but the structure is different:

• Egyptian: الشارع ده طويل
• MSA: هذا الشارع طويل

So if you are learning Egyptian, the version with ده is the natural everyday form.

Yes, but changing it can change the meaning or make it sound less natural.

The most natural Egyptian sentence for This street is long is:

الشارع ده طويل

If you say:

ده شارع طويل

that usually means:

This is a long street

So the position of ده matters.

• الشارع ده طويل = This street is long
• ده شارع طويل = This is a long street

Even though the words are similar, the sentence structure is doing different work.

Because in Egyptian Arabic, the noun is usually definite when used with a demonstrative like ده.

So الشارع ده literally contains both:

• الـ = the
• ده = this

But together they function naturally as this street.

This is just how Egyptian Arabic normally builds these expressions.
You should think of الشارع ده as one common pattern, not as awkwardly saying the this street.