الطاقة مهمة.

A common classroom pronunciation is aṭ-ṭāqa muhimma.

If you add full case endings, it is aṭ-ṭāqatu muhimmatun.

Two things to notice:

• ال is written, but the l sound is not pronounced here.
• That is because ط is a sun letter, so the article assimilates: al- + ṭ becomes aṭ-ṭ.

It is a complete sentence in Modern Standard Arabic.

This is a nominal sentence: a sentence with no verb in the present tense.

• الطاقة = the subject
• مهمة = the predicate

In traditional Arabic grammar, these are called مبتدأ and خبر.

So this is not just noun + adjective in the English sense. It functions as a full sentence.

Arabic usually leaves out the present-tense verb to be in sentences like this.

So Arabic says:

• الطاقة مهمة

where English says:

• Energy is important

This is completely normal. In the present tense, there is usually no separate word for is / am / are in this kind of sentence.

Because طاقة is a feminine noun, and Arabic adjectives agree with the noun they relate to.

So:

• مهم = masculine
• مهمة = feminine

Since طاقة is feminine, the predicate uses the feminine form مهمة.

The ending ة is the common feminine marker, called tāʾ marbūṭa.

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

Compare these:

• الطاقة مهمة = a sentence: Energy is important
• الطاقة المهمة = a noun phrase: the important energy

That is a very important difference in Arabic:

• definite noun + indefinite adjective/predicate can make a sentence
• definite noun + definite adjective makes a noun phrase

ال is the definite article, like the in English.

So:

• طاقة = energy
• الطاقة = the energy

However, Arabic often uses the definite form for general statements where English uses a bare noun. So although الطاقة is literally the energy, the natural English meaning may simply be energy in a general sense.

With full vowel marking, the sentence is:

الطاقةُ مهمةٌ

Both words are in the nominative case:

• الطاقةُ = nominative subject
• مهمةٌ = nominative predicate

In normal Arabic writing, these short vowels and case endings are usually not written, so learners commonly see just:

الطاقة مهمة

That letter is ة, called tāʾ marbūṭa.

It often marks feminine nouns and adjectives.

Here:

• طاقة is a feminine noun
• مهمة is the feminine form of the adjective

So the matching ة endings help show feminine agreement.

For a beginner, the safest and most neutral order is:

الطاقة مهمة

Arabic can sometimes place the predicate first for emphasis or style, but that is not the basic pattern you should learn first.

So for now, it is best to treat this sentence as:

• subject first
• predicate second