الحمولة ممتلئة.

Because this is a nominal sentence in Arabic. In the present tense, Arabic usually does not use a separate word for is/am/are.

So:

• الحمولة ممتلئة = The load is full

Arabic simply puts the subject first and the description after it.

If you want a past-tense was, then Arabic does use a verb:

• كانت الحمولة ممتلئة = The load was full

Because الحمولة is a feminine singular noun, and the predicate adjective must agree with it in gender and number.

So:

• masculine: ممتلئ
• feminine: ممتلئة

Since the subject is الحمولة, the correct form is:

• الحمولة ممتلئة

not:

• الحمولة ممتلئ

A big clue is the ending ة (taa marbuuṭa), which very often marks feminine nouns in Arabic.

So حمولة is grammatically feminine, and when you add ال, it becomes الحمولة.

Because it is feminine, the describing word must also be feminine:

• الحمولة ممتلئة

Keep in mind that grammatical gender in Arabic is a grammar feature, not necessarily a reflection of natural gender.

Because here ممتلئة is the predicate of the sentence, not an attributive adjective inside a noun phrase.

Compare these:

• الحمولة ممتلئة = The load is full
• الحمولة الممتلئة = the full load

This is a very important difference.

In الحمولة ممتلئة:

• الحمولة is the subject
• ممتلئة is what is being said about it

In الحمولة الممتلئة:

• both words are definite
• the second word is just modifying the noun
• it forms one noun phrase: the full load

It functions like an adjective here, but more specifically it is the feminine form of an active participle from the verb امتلأ meaning to be full / to become filled.

The basic forms are:

• امتلأ = he became full / it became full
• ممتلئ = full, filled up (masculine)
• ممتلئة = full, filled up (feminine)

So in this sentence, ممتلئة works as a predicate meaning full.

This is one of the most useful grammar distinctions in Arabic.

• الحمولة ممتلئة = The load is full
• الحمولة الممتلئة = the full load

Why?

Because in the first sentence:

• the second word is a predicate
• it tells you something about the subject

In the second expression:

• the second word is a true adjective
• it describes the noun within the same noun phrase
• both noun and adjective are definite

So if you add ال to ممتلئة, you change the structure and the meaning.

A careful pronunciation is roughly:

• al-ḥumūlah mumtaliʾah

A few helpful notes:

• ال is pronounced al- here because ح is a moon letter, so the l sound stays.
• ح is a strong breathy ḥ sound, not like ordinary English h.
• ممتلئة contains a hamza: ممتلئة
• that middle part is pronounced something like -taliʾ-

If pausing at the end, learners often say:

• al-ḥumūla mumtaliʾa

That is normal in pausal pronunciation.

The roots are:

• الحمولة ← root ح م ل = carrying, bearing, loading
• ممتلئة ← root م ل أ = filling, being full

This helps connect the vocabulary:

From ح م ل you get words related to carrying or loading, such as:

• حمل = to carry
• حمولة = load, cargo, payload

From م ل أ you get words related to filling:

• ملأ = to fill
• امتلأ = to become full
• ممتلئ / ممتلئة = full

In fully vocalized MSA, it would typically be:

• الحمولةُ ممتلئةٌ

That is:

• الحمولةُ with ḍamma because it is the subject
• ممتلئةٌ with ḍammatayn because it is an indefinite predicate

In normal everyday writing, these case endings are usually omitted, so you usually just see:

• الحمولة ممتلئة

Yes, you may also encounter:

• الحمولة مملوءة

This also means something like the load is full / filled.

A rough distinction:

• ممتلئة often feels like full, filled up
• مملوءة is more literally filled

In many contexts they are very close in meaning, and both are grammatical. Learners should mainly recognize that both can describe something as full.

The usual present-tense negation is:

• الحمولة ليست ممتلئة = The load is not full

Here ليست is the feminine singular form used because the subject الحمولة is feminine.

So you can compare:

• الحمولة ممتلئة = The load is full
• الحمولة ليست ممتلئة = The load is not full

It looks complicated because two things come together:

1. the word contains a hamza
2. it also takes the feminine ending ة

The masculine form is:

• ممتلئ

To make it feminine, Arabic adds ة:

• ممتلئ + ة → ممتلئة

The hamza is written on ئ here because of the spelling rules for hamza; the surrounding vowel environment favors this seat.

So even though the ending looks complex, grammatically it is just:

• the base form ممتلئ
• plus feminine ة

The normal neutral order is:

• الحمولة ممتلئة

That is the most straightforward way to say The load is full.

Putting ممتلئة first is much less neutral and can sound marked or stylistically special. For a learner, the standard pattern to remember is:

• subject + predicate

So the safest form is:

• الحمولة ممتلئة

It can vary by context. حمولة often refers to what is being carried or transported, so possible English translations include:

• load
• cargo
• payload
• shipment in some contexts

The exact choice depends on the situation. Grammatically, though, the sentence structure stays the same:

• الحمولة ممتلئة

So even if the English gloss changes by context, the Arabic grammar here does not.