السعر خاطئ.

A careful Modern Standard Arabic pronunciation is:

as-siʿru khāṭiʾ

A more natural pause-form, without full case endings, is often:

as-siʿr khāṭiʾ

A few pronunciation notes:

• السعر is written with ال, but because س is a sun letter, ال is pronounced as-, not al-.
• The middle sound ع in سعر is the consonant ʿayn, which does not exist in English.
• خاطئ ends with a hamza sound, a glottal stop: khā-ṭiʾ.

Because Arabic often leaves out the verb to be in the present tense.

So:

• السعر خاطئ = The price is wrong

This is a very common Arabic sentence pattern: subject + predicate, with no present-tense is/are.

Compare:

• الولد طويل = The boy is tall
• الجو جميل = The weather is nice

If you want the past or future, Arabic does use other words:

• كان السعر خاطئًا = The price was wrong
• سيكون السعر خاطئًا = The price will be wrong

Because س is one of the sun letters.

In Arabic, when ال comes before a sun letter, the l sound of ال is not pronounced. Instead, the following consonant is doubled.

So:

• written: السعر
• pronounced: as-siʿr

This happens in many words, for example:

• الشمس → ash-shams
• السماء → as-samāʾ
• السلام → as-salām

This is a very important difference.

• السعر خاطئ = The price is wrong
• السعر الخاطئ = the wrong price / the incorrect price

Why?

In السعر خاطئ:

• السعر is the subject
• خاطئ is the predicate

So the sentence means the price is wrong.

In السعر الخاطئ:

• الخاطئ is an adjective describing السعر

So it becomes a noun phrase: the wrong price.

This distinction is very common in Arabic:

• البيت كبير = The house is big
• البيت الكبير = the big house

Because it matches السعر, which is a masculine singular noun.

In Arabic, predicates and adjectives usually agree with the noun in gender and often in number.

So:

• السعر خاطئ = masculine singular
• القيمة خاطئة = feminine singular

Notice how the feminine form adds ة:

• masculine: خاطئ
• feminine: خاطئة

In fully inflected MSA, the sentence is:

السِّعْرُ خاطِئٌ

That means:

• السعرُ has ḍamma because it is the subject of the sentence
• خاطئٌ also has ḍamma/tanwīn because it is the predicate

However, in most everyday pronunciation, especially outside very formal reading, these endings are often not pronounced fully. So learners often hear something closer to:

السعر خاطئ

or pronounced:

as-siʿr khāṭiʾ

So both are useful to know:

• full grammatical form: السِّعْرُ خاطِئٌ
• common pause/spoken form: السعر خاطئ

That is a hamza written on a yāʾ seat.

The word is pronounced:

khā-ṭiʾ

So the end is not just -i. It ends with a glottal stop after that vowel.

Why is it written ئ here?
Because in standard spelling, the shape of the hamza often depends on the vowel before it. Here, the vowel before the hamza is i, so the hamza sits on ئ.

For a learner, the most important thing is pronunciation:

• خاطئ = khāṭiʾ
• not khāṭi
• not khāṭī

No. خاطئ means wrong, incorrect, or mistaken.

So السعر خاطئ means the price is incorrect, for example on a label, bill, or website.

If you want to say the price is expensive/high, Arabic usually uses other words, such as:

• السعر مرتفع = The price is high
• السعر غالٍ or السعر غالي = The price is expensive

So these are different ideas:

• خاطئ = wrong/incorrect
• مرتفع / غالٍ = expensive/high

Yes, generally خاطئ is more standard and fits Modern Standard Arabic well.

• خاطئ = standard/formal, very suitable in MSA
• غلط = common and widely understood, but often felt to be more colloquial or less formal depending on context

So in a textbook or formal written Arabic, السعر خاطئ is a very natural choice.

You may also see:

• هذا خطأ = This is a mistake
• السعر غير صحيح = The price is not correct

All of these are related, but خاطئ is a very standard MSA adjective.