دي خطوة مهمة.

دي means this in Egyptian Arabic.

More specifically, it is the feminine singular form of this. Since خطوة (step) is a feminine noun, دي is the correct choice.

A rough pronunciation is di.

Because خطوة is feminine.

In Egyptian Arabic:

• ده = this for masculine nouns
• دي = this for feminine nouns

So:

• ده كتاب = this is a book / this book
• دي خطوة = this is a step / this step

Even though step is not feminine in English, nouns in Arabic have grammatical gender, and خطوة is feminine.

In Arabic, the verb to be in the present tense is usually not stated.

So دي خطوة مهمة literally looks like:

• دي = this
• خطوة = step
• مهمة = important

But the natural English meaning is:

• This is an important step

This is very normal in both Egyptian Arabic and Standard Arabic-style structures.

خطوة means step.

In Egyptian Arabic, it is commonly pronounced something like khotwa or khotwa(h).

A few notes:

• The first consonant خ is the throaty sound like German Bach or Scottish loch
• The ة at the end is the feminine ending, usually sounding like -a in pause

So a learner-friendly pronunciation is:

• خطوة = KHOT-wa

Because adjectives in Arabic usually agree with the noun they describe.

Since خطوة is feminine singular, the adjective important also has to be feminine singular:

• masculine: مهم
• feminine: مهمة

So:

• أمر مهم = an important matter
• خطوة مهمة = an important step

This is called adjective agreement.

The sentence is:

• دي
  • خطوة
    • مهمة

Literally:

• this
  • step
    • important

Natural English:

• This is an important step

Here, دي is functioning like this is...

Also notice that:

• the noun comes before the adjective
• the adjective follows the noun it describes

So خطوة مهمة is literally step important, which means an important step.

Because مهم is masculine, and خطوة is feminine.

You need:

• مهم with masculine nouns
• مهمة with feminine nouns

So:

• كتاب مهم = an important book
• خطوة مهمة = an important step

Using مهم after خطوة would sound grammatically wrong.

They are related, but not exactly the same structure.

• دي خطوة مهمة = This is an important step
• الخطوة دي مهمة = This step is important

In الخطوة دي مهمة, the noun phrase الخطوة دي means this step.

So the difference is:

1. دي خطوة مهمة

   • starts with this
   • means This is an important step

2. الخطوة دي مهمة

   • starts with the step this
   • means This step is important

Both are natural in Egyptian Arabic, but they are structured differently.

It is usually pronounced mohimma in Egyptian Arabic.

A helpful breakdown:

• mo-HIM-ma

The doubled m sound comes from the spelling pattern, so you should make the middle m a little stronger than in English.

So the whole sentence can be pronounced approximately as:

• di khotwa mohimma

This sentence is natural in Egyptian Arabic.

The word دي is a strong clue that this is Egyptian (and colloquial) rather than Standard Arabic.

In Standard Arabic, you would more likely see something like:

• هذه خطوة مهمة

Both mean the same thing, but:

• دي خطوة مهمة = Egyptian Arabic
• هذه خطوة مهمة = Standard Arabic

Yes, in a sentence like this, دي is often best understood as this is in English.

That is because Arabic does not need a present-tense is here.

So although دي itself basically means this, the full sentence naturally becomes:

• This is an important step

That is why learners often feel like دي is doing extra work in translation. It is not literally a separate word for is—English just needs one, while Arabic does not.