El testamento incluye la disposición testamentaria.

Because Spanish nouns have grammatical gender.

• testamento is masculine, so it takes el
• disposición is feminine, so it takes la

This is grammatical gender, not biological gender. In this sentence, you just have to learn each noun with its article.

A useful pattern:

• nouns ending in -mento are usually masculine
• nouns ending in -ción are usually feminine

So:

• el testamento
• la disposición

Incluye is the third person singular present indicative of incluir.

So it matches el testamento:

• yo incluyo
• tú incluyes
• él/ella/usted incluye

Here, el testamento is the subject, so Spanish uses incluye = includes.

Spanish often uses the definite article more than English does.

Here, la disposición testamentaria refers to a specific legal provision, so la sounds natural. It suggests a particular provision being discussed or identified in context.

If you said incluye una disposición testamentaria, that would mean it includes a testamentary provision, which is less specific.

So the choice between la and una depends on whether the provision is specific or indefinite.

Not here. Disposición has several meanings depending on context.

Common meanings include:

• arrangement
• disposition
• willingness/readiness
• provision/clause/ruling in legal language

In this sentence, it is being used in a legal sense: a provision, clause, or stipulation in a will.

So although English disposition can refer to personality, that is not the meaning here.

In Spanish, adjectives usually come after the noun, especially when they classify or specify the type of thing.

So:

• disposición testamentaria = a disposition/provision of a testamentary kind

This is the normal order in formal Spanish, especially in legal language.

Putting the adjective before the noun would sound unusual here and could change the tone or emphasis.

Because it has to agree with disposición, which is feminine singular.

Spanish adjectives agree with the noun they describe in:

• gender
• number

So:

• disposición testamentaria → feminine singular
• acto testamentario → masculine singular
• disposiciones testamentarias → feminine plural

This agreement is a key feature of Spanish grammar.

Often, yes. Both can express the idea of related to the will.

Compare:

• la disposición testamentaria
• la disposición del testamento

Both are possible, but they are not always identical in tone.

• testamentaria sounds more formal, technical, and legal
• del testamento is often more transparent for learners and slightly less compact

Legal Spanish often prefers the adjective form because it sounds precise and conventional.

Sometimes, but you should be careful.

In modern everyday English, the legal document is usually called a will, while testament sounds old-fashioned or is more common in religious expressions such as the New Testament.

In Spanish, testamento is the normal everyday legal word for will.

So even though the words are related, the most natural English equivalent in legal everyday use is usually will, not testament.

It is natural, but it sounds formal and legal.

That is because of words like:

• testamento
• disposición
• testamentaria

This is the kind of wording you might see in:

• legal documents
• official explanations
• notarial language
• law-related discussion

In everyday conversation, people might use simpler wording if they were not speaking in a legal context.

Yes. It follows the standard pattern:

Subject + verb + object

• El testamento = subject
• incluye = verb
• la disposición testamentaria = direct object

That is a very normal and straightforward Spanish sentence structure.

A simple pronunciation guide:

• testamento → tes-ta-MEN-to
• incluye → in-CLU-ye
• disposición → dis-po-si-CIÓN
• testamentaria → tes-ta-men-TA-ria

A few useful notes:

• ción is pronounced roughly like thyón in Spain and often like syón in much of Latin America
• the stress falls where the capital letters are above
• incluye contains y, which sounds like a consonant sound, roughly similar to English y in many learner-friendly explanations

Yes, depending on nuance.

Possible alternatives include:

• contiene
• recoge
• establece

But they are not always exact synonyms.

• incluye = includes
• contiene = contains
• recoge in legal Spanish can mean something like sets out / contains / includes in a formal way
• establece = establishes / states

So incluye is correct and clear, but legal Spanish may use several different verbs depending on the exact context.