يدفع أمر الدفع المستديم القسط.

It follows the common Arabic pattern verb + subject + object:

• يدفع = pays
• أمر الدفع المستديم = the standing payment order
• القسط = the installment

So the literal order is:

• pays
  • the standing payment order
    • the installment

In natural English, that becomes The standing payment order pays the installment.

Because Arabic uses the same 3rd person masculine singular verb form for:

• he
• it for a masculine singular noun

The subject here is أمر (order), which is a masculine singular noun, so يدفع is the correct form.

So يدفع can mean:

• he pays
• it pays

You decide from the context.

Because أمر الدفع is an iḍāfa construction, often called a construct phrase.

In an iḍāfa:

• the first noun usually does not take ال
• the second noun can make the whole phrase definite

So:

• أمر دفع = a payment order
• أمر الدفع = the payment order

Even without ال on أمر, the whole phrase can still mean the ... because الدفع is definite.

Yes. Literally, أمر الدفع is:

• أمر = order
• الدفع = the payment / paying

So word-for-word it is something like order of payment.

In smoother English, that becomes:

• payment order
• in banking contexts, often standing order if more context is present

This is a very normal way Arabic links nouns together.

It is intended to describe the whole noun phrase أمر الدفع, giving the sense standing / ongoing / permanent.

So the intended meaning is:

• أمر الدفع المستديم = the standing payment order

However, this is a good place to notice something important:

In unvowelled Arabic writing, المستديم could look ambiguous. Case endings are not written, so a learner may not immediately know whether it modifies:

• أمر (order), or
• الدفع (payment)

If the intended meaning is standing payment order, then in full grammatical reading it would modify أمر.

If the intended meaning is The standing payment order pays the installment, a fully vocalized reading would be:

يَدْفَعُ أَمْرُ الدَّفْعِ المُسْتَدِيمُ القِسْطَ

The endings show the grammar:

• يَدْفَعُ = verb
• أَمْرُ = subject, so nominative
• الدَّفْعِ = second term of iḍāfa, so genitive
• المُسْتَدِيمُ = adjective describing أمر, so nominative
• القِسْطَ = direct object, so accusative

In normal everyday writing, those short vowels are usually omitted.

القسط is the direct object: it is the thing being paid.

Arabic often places the sentence in this order:

• verb
• subject
• object

So القسط comes last because it is the object of يدفع.

If fully vowelled, it would be القسطَ to show the accusative case.

Yes. Because it has ال, it means the installment, not just an installment.

So:

• قسط = an installment
• القسط = the installment

In real context, this usually means a specific known installment, for example one already mentioned or understood from the situation.

Yes. That would be a subject-first sentence instead of a verb-first sentence.

So both are possible:

• يدفع أمر الدفع المستديم القسط
• أمر الدفع المستديم يدفع القسط

The difference is mostly one of style, focus, and sentence rhythm. Both are grammatical.

In this particular sentence, the verb form stays the same because the subject is singular masculine.

No. Its basic sense is broader and can include ideas like push or drive forward.

But in financial contexts, دفع very commonly means:

• to pay

So here يدفع is naturally understood as pays.

This is very common in Arabic: one root can have several related meanings depending on context.

Yes, المستديم works, and it means something like:

• continuous
• ongoing
• standing
• permanent

In banking or administrative language, Arabic may also use words like:

• دائم = permanent / ongoing

So you may also encounter expressions such as:

• أمر دفع دائم

Depending on region and institution, one wording may sound more common than another, but المستديم is understandable and formal.

Yes, but only to a reasonable degree.

Most real Arabic text is written without short vowels, so learners must learn to infer grammar from:

• word order
• common patterns
• iḍāfa structure
• context

In this sentence, even without the written endings, an experienced reader can still recognize:

• يدفع as the verb
• أمر الدفع المستديم as the subject phrase
• القسط as the object

So this is a normal part of reading Arabic, not a special problem with this sentence.