الجهاز المنزلي يستهلك طاقة.

الـ is the Arabic definite article, equivalent to the in English.

So:

• جهاز = a device / device
• الجهاز = the device

In this sentence, الجهاز is made definite, so it refers to the device or, more naturally together with the adjective, the household device / the home appliance.

Because in Arabic, an adjective normally matches the noun it describes in definiteness.

So if the noun is definite, the adjective must also be definite:

• جهاز منزلي = a household device
• الجهاز المنزلي = the household device

This is different from English, where only the appears once: the household device.
In Arabic, both parts show definiteness.

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

So:

• الجهاز = the device
• المنزلي = domestic / household / home-related

Together:

• الجهاز المنزلي = the household device

This noun-then-adjective order is the normal Arabic pattern.

المنزلي is an adjective derived from منزل (house, home).

It means something like:

• domestic
• household
• home

The ending -ي is a very common way in Arabic to form a relational adjective, often called a nisba adjective.

Examples:

• مصر → مصري = Egyptian
• منزل → منزلي = domestic / home-related

So الجهاز المنزلي literally means the home-related device, i.e. the household appliance/device.

يستهلك is the present/imperfect form meaning he consumes / it consumes / is consuming / consumes.

In this sentence, it agrees with الجهاز, which is:

• singular
• masculine

So the verb is also singular masculine.

You can think of يستهلك here as meaning:

• it consumes

because الجهاز is an inanimate masculine noun, and Arabic uses the same 3rd-person masculine singular verb form for that.

In the present/imperfect tense, Arabic verbs often begin with a prefix that shows the subject.

Here, يـ marks third person masculine singular:

• يستهلك = he consumes / it consumes

Other common present-tense prefixes include:

• أـ = I
• تـ = you or she
• نـ = we

So the يـ tells you the subject is he/it.

Because it is indefinite here.

• طاقة = energy
• الطاقة = the energy

In this sentence, the meaning is general: the device consumes energy, not some specific previously mentioned energy.

That is why طاقة appears without الـ.

طاقة is the direct object of the verb يستهلك.

So the structure is:

• الجهاز المنزلي = the subject noun phrase
• يستهلك = the verb
• طاقة = what is being consumed

In other words:

• The household device → consumes → energy

Yes. In fully vowelled, formal MSA, the sentence would typically be:

الجهازُ المنزليُّ يستهلكُ طاقةً

Those endings show grammatical case and mood:

• الجهازُ → nominative
• المنزليُّ → nominative, matching the noun
• يستهلكُ → indicative
• طاقةً → accusative, because it is the direct object

In normal everyday writing, these short vowel endings are usually omitted, so you often just see:

الجهاز المنزلي يستهلك طاقة

Because it is:

• indefinite
• a direct object

An indefinite direct object is commonly marked with tanwīn fatḥ (ً) in formal Arabic.

So:

• طاقة → basic written form
• طاقةً → fully vocalized grammatical form

This is one reason learners often hear about Arabic “case endings,” even though they are usually not written in ordinary texts.

It begins with a noun phrase, so many learners think of it as a nominal sentence pattern:

• الجهاز المنزلي = topic/subject
• يستهلك طاقة = predicate/comment

But the predicate itself is a verb phrase.

So a simple practical way to understand it is:

• The sentence starts with a noun
• Then it says what that noun does

That is completely normal in Arabic.

Yes. That is also correct Arabic.

Both are possible:

• الجهاز المنزلي يستهلك طاقة
• يستهلك الجهاز المنزلي طاقة

The difference is mainly one of style and focus:

• Starting with الجهاز المنزلي puts focus on the household device
• Starting with يستهلك presents the action first: consumes

Arabic allows more flexibility in word order than English, as long as the grammar is clear.

You can tell from the pattern of agreement.

المنزلي matches الجهاز in:

• definiteness: both have الـ
• gender: both are masculine singular
• number: both are singular

That is exactly what Arabic adjectives do.

So الجهاز المنزلي is understood as:

• noun + adjective
• the household device

not as two separate unrelated nouns.

Here, the l in الـ is pronounced normally.

That is because ج in الجهاز is a moon letter, not a sun letter.

So you pronounce it approximately as:

• al-jihāz

Likewise in المنزلي:

• al-manzilī

because م is also a moon letter.

So in both words, the l of الـ stays audible.

No, not here.

Even though طاقة is a feminine noun, it is the object, not the subject.
The verb agrees with the subject, which is الجهاز.

So the verb stays:

• يستهلك = it consumes

If طاقة were the subject of a different sentence, then its femininity could matter for agreement.

Yes, it can be useful.

يستهلك comes from the verb استهلك, which is commonly associated with the root ه ل ك.

The basic idea of the root is connected historically with perishing / being used up / being destroyed, and in this derived form استهلك it means to consume, use up.

For a learner, the most important practical point is simply:

• استهلك = to consume
• يستهلك = he/it consumes

You do not need deep root knowledge to understand the sentence, but it can help you recognize related vocabulary later.

Yes, it is understandable and natural in MSA.

Depending on context, Arabic may also use other expressions, but الجهاز المنزلي works well for household device / home appliance.

A learner should notice that Arabic often builds these meanings with:

• a noun: جهاز
• plus a descriptive adjective: منزلي

rather than using a single compound word the way English sometimes does.

Usually, in everyday careful speech, many speakers do not fully pronounce all case endings, especially outside very formal contexts.

So learners commonly say:

• الجهاز المنزلي يستهلك طاقة

without explicitly saying all the final -u and -an endings.

In very formal recitation, newsreading, or grammar-focused settings, the full endings may be pronounced:

• الجهازُ المنزليُّ يستهلكُ طاقةً

So both are worth recognizing, but for many learners the unvowelled everyday version is the one they will hear and use most often.