ההזמנה על הטלפון שלי, אבל מה שחשוב הוא הכתובת הנכונה.

In Hebrew, the verb to be is usually omitted in the present tense.

So ההזמנה על הטלפון שלי literally looks like the order/invitation on my phone, but it means the order/invitation is on my phone.

This is very normal Hebrew.
Compare:

• הספר על השולחן = the book is on the table
• אני בבית = I am at home

If you wanted to be more explicit, you could sometimes use a verb like נמצאת or נמצא/נמצאת, depending on the noun:

• ההזמנה נמצאת על הטלפון שלי = the order/invitation is located on my phone

But the version without a verb is completely standard.

הזמנה can mean several related things, depending on context:

• invitation
• order (for example, an online purchase)
• reservation/booking

So the exact meaning depends on the situation. If the meaning has already been shown to the learner, the important thing to know is that this noun is flexible and often needs context.

Its form here is ההזמנה = the invitation/order/reservation.

The prefix ה־ is the Hebrew definite article, equivalent to the in English.

So:

• הזמנה = an invitation / an order / a reservation
• ההזמנה = the invitation / the order / the reservation

Because the sentence is talking about a specific one, Hebrew uses ה־.

You may notice that it becomes ההזמנה with two ה letters in a row. That is normal: one ה is part of the word itself, and the other is the article prefix.

Yes. על usually means on, and in modern Hebrew it can also be used for something displayed, stored, or accessible on a phone or on a device.

So על הטלפון שלי can mean something like:

• on my phone
• on my phone screen
• on my phone/device

That said, native speakers might also say:

• בטלפון שלי = in/on my phone
• אצלי בטלפון = on my phone / with me on my phone

So על הטלפון שלי is understandable, but depending on context, בטלפון שלי may sound more natural to some speakers.

In Hebrew, possession with של usually comes after the noun.

So:

• הטלפון שלי = my phone
• הבית שלהם = their house
• החברה שלנו = our company

This is the normal pattern. English puts the possessor first (my phone), but Hebrew usually puts it after the noun.

So הטלפון שלי is literally the phone of me, but naturally it means my phone.

מה שחשוב means what is important or what matters.

It is made of:

• מה = what
• ש־ = that / which
• חשוב = important

So literally it is something like that which is important.

This is a very common Hebrew structure:

• מה שאני רוצה = what I want
• מה שהוא אמר = what he said
• מה שחשוב = what is important / what matters

For English speakers, the little ש־ is especially important, because Hebrew often uses it where English would not explicitly say that.

The prefix ש־ is a very common Hebrew particle meaning that, which, or sometimes introducing a relative clause.

In מה שחשוב, it links מה to חשוב:

• מה = what
• שחשוב = that is important

So together: what is important.

Without ש־, the phrase would not sound right in standard Hebrew. It is a key part of the structure.

You will see ש־ everywhere in everyday Hebrew:

• אני חושב ש... = I think that...
• הספר שקניתי = the book that I bought
• מה שקרה = what happened

Excellent question. Hebrew often omits is in the present tense, but in sentences where one side is a full definite phrase and the other side is also a definite phrase, speakers often use הוא or היא as a kind of present-tense linking word.

So:

• מה שחשוב הוא הכתובת הנכונה = what matters is the correct address

Here הוא helps connect the two sides clearly.

This use is especially common when:

• the subject is long or complex
• both parts are definite
• the speaker wants a clear, balanced sentence

English speakers often expect either always having is or never having it, but Hebrew is more flexible. In simple sentences, there is usually no present-tense is. In more formal or structured equational sentences, הוא/היא may appear.

Because the phrase is definite: the correct address.

In Hebrew, when a noun is definite and it has an adjective, the adjective also becomes definite.

So:

• כתובת נכונה = a correct address
• הכתובת הנכונה = the correct address

This is a very important rule in Hebrew adjective phrases.

More examples:

• ספר טוב = a good book
• הספר הטוב = the good book

Both the noun and the adjective take ה־ when the whole phrase is definite.

Because כתובת is a feminine singular noun, and Hebrew adjectives must agree with the nouns they describe in gender and number.

So:

• כתובת = feminine singular
• therefore נכונה = feminine singular adjective

Compare:

• כתובת נכונה = a correct address
• מספר נכון = a correct number

Here מספר is masculine, so the adjective is נכון, not נכונה.

This agreement rule is one of the most important features of Hebrew grammar.

Yes. A very natural alternative would be:

• אבל הכתובת הנכונה היא מה שחשוב

This means the same thing: but the correct address is what matters.

The original version:

• אבל מה שחשוב הוא הכתובת הנכונה

puts more focus first on what matters.

The alternative version puts the focus first on the correct address.

Both are grammatical. The difference is mainly one of emphasis and style.