Telefonum düzelir düzelmez sana mesaj atacağım.

This is a very common Turkish pattern:

verb-aorist + verb-negative-aorist

So here:

• düzelir = it gets better / it is fixed
• düzelmez = it doesn’t get better / it isn’t fixed

But together, düzelir düzelmez does not mean it gets better, it doesn’t get better. As a fixed structure, it means:

• as soon as it gets fixed
• the moment it gets fixed

So the repetition is grammatical, not stylistic.

Not really in meaning.

By itself, düzelmez would normally mean it does not get fixed / it won’t get better.

But in the pattern düzelir düzelmez, the whole expression functions as one time clause meaning as soon as it gets fixed.

So although the second part looks negative in form, the overall meaning is not negative.

Because Turkish often expresses that idea with a verb pattern instead of a separate conjunction.

English uses a phrase like:

• as soon as my phone is fixed

Turkish can do that with:

• telefonum düzelir düzelmez

So instead of adding a separate word meaning as soon as, Turkish builds that meaning directly onto the verb.

This is very natural in Turkish.

Telefonum means my phone.

It is made of:

• telefon = phone
• -um = my

So:

• telefon → phone
• telefonum → my phone

Turkish usually attaches possessive endings directly to the noun instead of using a separate word like my.

Because sana means to you, and that is what the verb needs here.

Breakdown:

• sen = you
• sana = to you

In sana mesaj atacağım, the message is directed to someone, so Turkish uses the dative ending.

This is very similar to the difference between:

• you
• to you

in English.

Yes, atmak literally often means to throw, to toss, or to send out.

But mesaj atmak is an idiomatic expression meaning:

• to send a message
• to text

This is just a normal Turkish collocation. Languages often use verbs in ways that are not fully literal.

So in this sentence:

• sana mesaj atacağım = I’ll send you a message / I’ll text you

Atacağım is the future tense, first person singular:

• at- = verb stem
• -acak / -ecek = future
• -ım / -im / -um / -üm = I

So:

• atacağım = I will send

Because of sound changes, it appears as atacağım, not a completely mechanical atacakım.

This is the normal future form of atmak for I.

Because Turkish often leaves subject pronouns out when the verb already shows who the subject is.

Here, atacağım already means I will send, so ben is unnecessary.

The full version could be:

• Telefonum düzelir düzelmez ben sana mesaj atacağım.

But that usually sounds more emphatic. In normal speech, Turkish often prefers to omit ben when it is obvious.

Yes, a sentence like this is also possible:

• Telefonum düzelince sana mesaj atacağım.

That means something like:

• When my phone gets fixed, I’ll message you.

The difference is nuance:

• düzelince = when it gets fixed
• düzelir düzelmez = as soon as it gets fixed / the moment it gets fixed

So düzelir düzelmez feels more immediate.

The given order is very natural:

• Telefonum düzelir düzelmez sana mesaj atacağım.

A common basic pattern in Turkish is:

time expression + indirect object + verb

So here:

• Telefonum düzelir düzelmez = time clause
• sana = to you
• mesaj atacağım = I will send a message

Turkish word order is flexible, though, especially for emphasis. For example, you might hear:

• Sana telefonum düzelir düzelmez mesaj atacağım.

That still works, but the original version is a very standard and natural way to say it.

Here düzelmek means something like:

• to get fixed
• to become normal again
• to improve

It is an intransitive verb, so the phone is not actively fixing something. Instead, the phone itself is the thing that becomes okay again.

Compare:

• düzeltmek = to fix something
• düzelmek = to get fixed / to improve

So:

• Telefonum düzelir = My phone gets fixed / starts working again
• Telefonumu düzeltirim = I fix my phone

That -mek / -tmek difference is important in Turkish.