يفصل قاطع الدائرة التيار الكهربائي.

Here يفصل means disconnects, separates, or cuts off.

In an electrical context, فصل often refers to interrupting a connection, so in this sentence it means that the circuit breaker interrupts the flow of current.

Grammatically, يفصل is:

• a present/imperfect tense verb
• 3rd person masculine singular
• from the root ف ص ل, which has the basic idea of separating or dividing

So يفصل = he/it disconnects.

Because Arabic often uses a verbal sentence structure, especially in Modern Standard Arabic.

The order here is:

• يفصل = the verb
• قاطع الدائرة = the subject
• التيار الكهربائي = the object

So the pattern is Verb – Subject – Object.

This is very common in Arabic. In English, we usually prefer Subject – Verb – Object, but Arabic frequently starts with the verb.

قاطع الدائرة means circuit breaker.

It is made of two nouns:

• قاطع = cutter, interrupter, breaker
• الدائرة = the circuit

Together, they form an iḍāfa construction, which is often called a genitive construction or noun annexation.

Literally, it is something like breaker of the circuit, but in natural English that becomes circuit breaker.

Because قاطع الدائرة is an iḍāfa construction.

In an iḍāfa:

• the first noun usually does not take ال
• the second noun can be definite or indefinite
• the definiteness of the whole phrase is determined by the second noun

So:

• قاطع دائرة = a circuit breaker or more literally a breaker of a circuit
• قاطع الدائرة = the circuit breaker or breaker of the circuit

Also, the first noun in iḍāfa does not take tanwīn.

Because it is the second term of an iḍāfa.

In قاطع الدائرة:

• قاطع is the first noun, called مضاف
• الدائرة is the second noun, called مضاف إليه

The second noun in an iḍāfa is in the genitive case.

In fully vowelled Arabic, you would see:

• قاطعُ الدائرةِ

But in normal unvowelled writing, those case endings are usually not shown.

In this sentence, يفصل is a transitive verb, so it needs something that is being disconnected.

The basic structure is:

• يفصل = disconnects
• قاطع الدائرة = the thing doing the action, so it is the subject
• التيار الكهربائي = the thing being disconnected, so it is the direct object

If the sentence were fully vowelled, the case endings would make this clearer:

• يفصلُ قاطعُ الدائرةِ التيارَ الكهربائيَّ

Here:

• قاطعُ = nominative, so it is the subject
• التيارَ = accusative, so it is the object

Without vowel marks, learners often rely on meaning and word order.

Because in a normal Arabic verb-first sentence, the verb is often singular even when the subject comes after it.

Here the subject is قاطع الدائرة, which is singular anyway, so يفصل is naturally singular masculine.

More generally:

• in verb-first word order, Arabic commonly uses a singular verb before a plural subject
• in subject-first word order, the verb usually agrees more fully

In this sentence, though, the subject is singular, so there is no conflict.

Because التيار الكهربائي means the electric current, and the adjective must match the noun.

Here:

• التيار = the current
• الكهربائي = electric / electrical

Since الكهربائي is describing التيار, it functions as an adjective, and adjectives in Arabic usually agree with the noun in:

• definiteness
• gender
• number
• case

So because التيار is definite, the adjective must also be definite:

• التيار الكهربائي = the electric current
• تيار كهربائي = an electric current

Here it is an adjective describing التيار.

So:

• التيار = current
• الكهربائي = electric / electrical

Together:

• التيار الكهربائي = the electric current

A learner might confuse this with an iḍāfa, but it is not one. It is a noun + adjective phrase, not noun + noun.

One easy clue is that both words have ال:

• in an iḍāfa, the first noun normally does not take ال
• in a noun + adjective phrase, both can be definite

Yes, that is also correct.

That version uses subject-first order:

• قاطع الدائرة = subject
• يفصل = verb
• التيار الكهربائي = object

So both are possible:

• يفصل قاطع الدائرة التيار الكهربائي
• قاطع الدائرة يفصل التيار الكهربائي

The first version sounds more like a typical verbal sentence. The second version is more subject-focused.

In this particular sentence, the meaning stays basically the same.

A careful pronunciation would be approximately:

yafṣilu qāṭiʿu d-dāʾirati at-tayyāra l-kahrabāʾiyya

If you want the fully vowelled form, it would be:

يَفْصِلُ قَاطِعُ الدَّائِرَةِ التَّيَّارَ الكَهْرَبَائِيَّ

A few pronunciation notes:

• ق is a deep q sound, not an English k
• ط is an emphatic t
• ع is a consonant with no exact English equivalent
• ال assimilates before ت in التيار, so it sounds like at-tayyār

If fully vowelled in careful Modern Standard Arabic, it would be:

يَفْصِلُ قَاطِعُ الدَّائِرَةِ التَّيَّارَ الكَهْرَبَائِيَّ

These endings show the grammar:

• يَفْصِلُ = verb
• قَاطِعُ = nominative, because it is the subject
• الدَّائِرَةِ = genitive, because it is the second part of the iḍāfa
• التَّيَّارَ = accusative, because it is the direct object
• الكَهْرَبَائِيَّ = accusative adjective agreeing with التَّيَّارَ

In normal printed Arabic, these short vowels are usually omitted, so learners have to infer them from grammar.