الكتاب ده جديد.

A common pronunciation is el-ketāb da gedīd.

A few useful notes:

• الكتاب → el-ketāb
• ده → da or dah
• جديد → gedīd

In Egyptian Arabic, ج is usually pronounced like g in go, not like the j in jam. So جديد sounds more like gedīd.

Word by word:

• الكتاب = the book
• ده = this for a masculine singular noun
• جديد = new

But the sentence is not translated word-for-word into natural English.
In Egyptian Arabic, الكتاب ده together means this book, so the whole sentence is:

This book is new.

Because in Egyptian Arabic, demonstratives like ده usually come after the noun.

So Egyptian Arabic says:

• الكتاب ده = this book

A native English speaker expects this book, with this first, but Egyptian Arabic normally puts it after the noun.

This is one of the big differences from English, and also from Standard Arabic, where you usually learn:

• هذا الكتاب = this book

In Egyptian Arabic, الكتاب ده is the normal everyday pattern.

In Arabic, the verb to be is usually omitted in the present tense when you are saying something like X is Y.

So:

• الكتاب ده جديد literally looks like this book new
• but it means This book is new

This is completely normal in Egyptian Arabic and in Standard Arabic too.

If you were talking about the past or future, then a verb can appear:

• الكتاب ده كان جديد = This book was new
• الكتاب ده هيبقى جديد = This book will be new

Because in Egyptian Arabic, the noun in this pattern is usually still marked as definite with الـ.

So the normal form is:

• الكتاب ده = this book

Not usually:

• كتاب ده

Think of الـ + noun + ده as the regular Egyptian way to say this + noun.

Because جديد here is a predicate adjective, not part of the noun phrase this book.

The sentence structure is:

• الكتاب ده = this book
• جديد = is new

So جديد is telling you something about the book.

Compare these:

• الكتاب ده جديد = This book is new
• الكتاب الجديد ده = This new book

In الكتاب الجديد ده, الجديد is directly describing the noun inside the noun phrase, so it takes الـ.

In الكتاب ده جديد, جديد is the predicate, so it does not take الـ.

Yes. ده is the masculine singular form.

كتاب is a masculine noun, so you use ده with it:

• الكتاب ده = this book

Useful comparisons:

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

For example:

• العربية دي جديدة = This car is new
• الكتب دي/دول جديدة = These books are new
  (In everyday speech, plural demonstrative usage can vary by region and style, but دول is the common standalone plural form.)

Yes, very normal.

The structure is:

• noun + ده/دي + adjective

So:

• الكتاب ده جديد = This book is new
• الولد ده طويل = This boy is tall
• البنت دي شاطرة = This girl is clever

This is one of the most common everyday patterns in Egyptian Arabic.

In Standard Arabic, you would usually say:

• هذا الكتاب جديد

In Egyptian Arabic, the everyday version is:

• الكتاب ده جديد

Main differences:

• Standard Arabic uses هذا before the noun
• Egyptian Arabic uses ده after the noun
• Egyptian pronunciation is also different

So if you already know Standard Arabic, this sentence is a good example of a very common colloquial Egyptian pattern.

Yes, but it means something slightly different.

• الكتاب ده جديد = This book is new
• ده كتاب جديد = This is a new book

So the first sentence talks about a specific book and says something about it.
The second sentence introduces or identifies something: This is a new book.

Both are correct, but they are not used in exactly the same way.