ما دامت شاحنة النقل متاحة، نحزم صناديق الكرتون.

ما دامت means as long as or so long as.

It introduces a condition that continues over a period of time. So the idea is not just if the truck is available, but more specifically while the truck remains available.

This is why ما دام / ما دامت is different from words like:

• إذا = if / when
• عندما = when

Here, ما دامت emphasizes an ongoing condition.

Because ما دام / ما دامت is a very common fixed expression in Arabic.

Even though دامت is formally a perfect verb form, the whole expression ما دامت functions like as long as in English and does not have to refer to past time.

So in this sentence, دامت is not really being felt as a simple past lasted. It is part of the structure that means as long as.

Because the subject is شاحنة (truck), and شاحنة is feminine singular.

So the verb agrees with it in gender:

• دام = masculine
• دامت = feminine

Since شاحنة النقل is feminine singular, Arabic uses دامت.

شاحنة النقل is an iḍāfa construction, often called a construct phrase.

It is made of:

• شاحنة = truck
• النقل = transport

Literally, it is something like the truck of transport, but natural English would be:

• the transport truck
• the delivery truck
• the transport vehicle
  depending on context

A key point about iḍāfa:

• the first noun usually does not take ال
• the second noun can take ال
• the whole phrase gets its definiteness from the second noun

So شاحنة النقل is definite because النقل is definite.

متاحة means available, and it describes شاحنة النقل.

It is feminine because شاحنة is feminine:

• متاح = available, masculine
• متاحة = available, feminine

In grammatical terms, this is the predicate of دامت.
Since دام behaves like كان in this expression, it takes:

• a subject
• a predicate

So in دامت شاحنة النقل متاحة:

• شاحنة النقل = the subject
• متاحة = the predicate

The imperfect نحزم is used because Arabic often uses the imperfect for:

• present actions
• repeated or habitual actions
• general statements
• near-future actions, depending on context

So نحزم here can naturally mean things like:

• we pack
• we are packing
• we pack whenever...
• we will pack, if the context is future-oriented

In this sentence, it fits the idea of what we do as long as that condition holds.

صناديق الكرتون is another iḍāfa construction.

It is made of:

• صناديق = boxes
• الكرتون = cardboard / carton

So the phrase means:

• cardboard boxes
• literally, boxes of cardboard

A useful vocabulary note:

• صندوق = box
• صناديق = boxes

This plural is a broken plural, which is very common in Arabic.

Arabic often uses iḍāfa to express type, material, or category in a compact way.

So صناديق الكرتون is a very natural way to say cardboard boxes.

You could also say صناديق من الكرتون, which more explicitly means boxes made of cardboard, but that wording can feel a bit more material-focused.

So the difference is roughly:

• صناديق الكرتون = cardboard boxes / carton boxes
• صناديق من الكرتون = boxes made of cardboard

Also, الكرتون stays singular because it is being used as a material/type noun, much like English cardboard in cardboard boxes.

A fully vocalized version would be:

ما دامتْ شاحنةُ النقلِ متاحةً، نحزمُ صناديقَ الكرتونِ.

If you want to see the grammar behind the endings:

• دامتْ = perfect verb
• شاحنةُ = nominative, because it is the subject of دامت
• النقلِ = genitive, because it is the second term of an iḍāfa
• متاحةً = accusative, because it is the predicate of دامت
• نحزمُ = imperfect verb
• صناديقَ = accusative, because it is the direct object of نحزم
• الكرتونِ = genitive, because it is the second term of an iḍāfa

In normal Arabic writing, these short vowels are usually omitted. In everyday speech, many of them are also not pronounced fully.