شهية القطة جيدة.

Because this is a nominal sentence in Arabic. In the present tense, Arabic usually does not use a separate verb for is/are.

So:

• شهية القطة جيدة literally looks like:
• the cat’s appetite good

But in natural English, it means:

• The cat’s appetite is good.

This is very normal in Arabic. The idea of is is understood without saying it.

Because شهية القطة is an iḍāfa construction, often called a possessive construction.

In an iḍāfa:

• the first noun does not take الـ
• the second noun can be definite, and that makes the whole phrase definite

So here:

• شهية = appetite
• القطة = the cat

Together:

• شهية القطة = the cat’s appetite

Even though شهية has no الـ, the whole phrase is definite because القطة is definite.

They form an iḍāfa phrase, which is one of the most common Arabic structures.

It works like:

• X of Y or
• Y’s X

So:

• شهية القطة = the appetite of the cat = the cat’s appetite

In this structure:

1. شهية is the thing possessed
2. القطة is the possessor

Also, in iḍāfa:

• the first noun does not take الـ
• the second noun is in the genitive case if fully vocalized

Because it agrees with شهية, and شهية is a feminine noun.

In Arabic, adjectives usually agree with the noun they describe in:

• gender
• number
• definiteness
• case

Here, جيدة matches شهية because شهية is feminine singular.

So:

• masculine: جيد
• feminine: جيدة

Even though القطة is also feminine, the adjective جيدة is agreeing with شهية, not directly with القطة.

It is both:

• it is an adjective in form
• but in this sentence it functions as the predicate of the nominal sentence

So the sentence structure is:

• شهية القطة = subject/topic
• جيدة = predicate/comment

In other words:

• The cat’s appetite → is good

So جيدة is not attached to القطة as an adjective meaning the good cat.
It is describing the whole subject phrase شهية القطة.

A common pause pronunciation is:

• shahiyyat al-qiṭṭa jayyida

If you pronounce the full case endings in careful MSA, it is:

• shahiyyatu l-qiṭṭati jayyidatun

A few notes:

• شهية is roughly shahiyya / shahiyyah
• القطة is al-qiṭṭa
• جيدة is jayyida

When reading naturally in pause, final case vowels are usually not pronounced.

In fully vocalized classical/MSA grammar, the sentence is:

• شَهِيَّةُ الْقِطَّةِ جَيِّدَةٌ

Case roles:

• شهيةُ: nominative, because it is the beginning of the nominal sentence
• القطةِ: genitive, because it is the second term of an iḍāfa
• جيدةٌ: nominative, because it is the predicate

So if you want the full grammatical reading:

• shahiyyatu l-qiṭṭati jayyidatun

In normal unvocalized writing, these endings are usually omitted.

Because it means the cat.

The definite article الـ makes a noun definite, like the in English.

So:

• قطة = a cat / cat
• القطة = the cat

And because القطة is definite, the whole iḍāfa phrase شهية القطة becomes definite too.

Both words exist, but they are not exactly the same.

• قطة usually refers to a female cat, and it is very commonly used for cat
• قط can refer to a male cat, and sometimes more generally to cat

In your sentence, القطة is used, so the meaning is specifically the female cat’s appetite, or just the cat’s appetite if the context is not focusing on sex.

For a learner, the important thing is that قطة is a very common word for cat.

Yes, but شهية القطة جيدة is the most straightforward and neutral order.

This order is:

• subject first
• predicate second

That is the normal pattern for a simple nominal sentence.

Arabic can sometimes change word order for emphasis or style, but for learners, this sentence is the best standard model:

• شهية القطة جيدة

Because it is the predicate, not an attributive adjective inside a noun phrase.

Compare these two ideas:

1. شهية القطة جيدة

   • The cat’s appetite is good
   • Here جيدة is the predicate, so it is usually indefinite

2. الشهية الجيدة

   • the good appetite
   • Here الجيدة is a regular adjective describing a noun inside a noun phrase, so it matches it in definiteness

So in your sentence, جيدة is indefinite because it is not part of a phrase like the good appetite. It is saying something about the subject: is good.

A natural MSA way is:

• شهية القطة ليست جيدة.

This uses ليست because شهية is feminine singular.

Compare:

• شهية القطة جيدة. = The cat’s appetite is good.
• شهية القطة ليست جيدة. = The cat’s appetite is not good.

So this is a useful pattern to remember:

• [subject] + جيدة = is good
• [subject] + ليست جيدة = is not good

Yes, شهية is a common word meaning appetite.

It is a feminine singular noun, which is why the predicate is feminine:

• شهية ... جيدة

It can appear in many similar phrases, for example:

• شهية الطفل جيدة = The child’s appetite is good.
• شهية المريض ضعيفة = The patient’s appetite is weak.

So this sentence is a very useful model for talking about health, food, and condition.

Two things are especially worth noticing:

1. The ط is doubled because of the shadda

   • so it is pronounced something like qiṭ-ṭa, not just qiṭa

2. The الـ is fully pronounced here

   • because ق is a moon letter, not a sun letter
   • so you say al-qiṭṭa, not aq-qiṭṭa

This makes the word sound like:

• al-qiṭṭa

That doubled consonant is important in accurate pronunciation.