القهوة ممتازة.

In Arabic, present-tense sentences like The coffee is excellent usually do not use a verb meaning is.

So:

• القهوة ممتازة = The coffee is excellent

This is called a nominal sentence in Arabic.
If you wanted the past or future, then Arabic would use other forms, but in the simple present, is/am/are is normally omitted.

ال is the Arabic definite article, meaning the.

So:

• قهوة = coffee
• القهوة = the coffee

In this sentence, القهوة is definite, so it means a specific coffee or coffee in a general definite sense, depending on context.

The ة (called taa marbuuTa) usually marks a word as feminine.

Here, قهوة is a feminine noun, so the adjective describing it must also be feminine:

• قهوة = feminine
• ممتازة = feminine form of excellent

This is a normal agreement pattern in Arabic: adjectives match the noun in gender.

Yes, قهوة is treated as a feminine noun in Modern Standard Arabic.

That is why you say:

• القهوة ممتازة

and not:

• القهوة ممتاز

Because the adjective must agree with قهوة in gender.

Because ممتازة here is the predicate of the sentence, not an adjective inside a noun phrase.

Compare:

• القهوة ممتازة = The coffee is excellent
• القهوة الممتازة = the excellent coffee

This is an important difference:

1. القهوة ممتازة

   • complete sentence
   • The coffee is excellent

2. القهوة الممتازة

   • noun + adjective phrase
   • the excellent coffee

In Arabic, when the second word is a predicate like excellent, it is usually indefinite, so it does not take ال.

It is an adjective in form, but in this sentence it functions as the predicate.

So grammatically, it is telling you something about القهوة:

• القهوة = the topic / subject
• ممتازة = what is being said about it

In English, we also use an adjective this way in The coffee is excellent.
So it is an adjective, but it is being used predicatively, not attributively.

In Arabic, adjectives normally come after the noun they describe.

So if you want to say:

• excellent coffee → قهوة ممتازة
• the excellent coffee → القهوة الممتازة

And in a sentence like:

• القهوة ممتازة

the predicate also comes after the subject.
So the word order is very natural in Arabic.

It is usually pronounced approximately as:

• al-qahwa

A few helpful notes:

• ق is a deep q sound, not the English k
• ه is a clear h
• the final ة in قهوة is usually pronounced like -a in pause

So in careful citation form, learners often say something like al-qah-wa.

It is usually pronounced approximately as:

• mumtaaza

Helpful breakdown:

• م = m
• م = m
• تاز gives the long aa sound
• final ة is usually pronounced -a in pause

So the whole word sounds roughly like mum-taa-za.

Yes, but the meaning changes.

• القهوة ممتازة = The coffee is excellent
• قهوة ممتازة can mean excellent coffee or, in some contexts, A coffee is excellent, though that second meaning is less natural without more context

So if you want a full sentence meaning The coffee is excellent, القهوة ممتازة is the clearest form.

In full formal grammar, yes.

The fully vowelled sentence would be:

• القهوةُ ممتازةٌ

with case endings:

• القهوةُ = nominative
• ممتازةٌ = nominative, indefinite

But in normal Arabic writing, these short vowel endings are usually not written, so you normally see:

• القهوة ممتازة

Learners should recognize that the sentence is correct even without the endings being shown.

They are the masculine and feminine forms of the same adjective:

• ممتاز = masculine excellent
• ممتازة = feminine excellent

Examples:

• الكتاب ممتاز = The book is excellent
  (كتاب is masculine)

• القهوة ممتازة = The coffee is excellent
  (قهوة is feminine)

So the ending changes to match the gender of the noun.

Sometimes, yes, depending on context.

Although القهوة literally has the, Arabic often uses the definite article in ways that can sound more general than English. So in some contexts, القهوة ممتازة could be understood as a general statement like Coffee is excellent.

But the most direct basic translation is still:

• The coffee is excellent

Context decides whether it is about a specific coffee or coffee more generally.