La portabilidad móvil es posible.

Because portabilidad is a feminine singular noun in Spanish, so it takes the feminine singular definite article la.

• la portabilidad = the portability
• Nouns ending in -dad are very often feminine:
  • la ciudad
  • la posibilidad
  • la realidad

So la agrees with portabilidad in gender and number.

Portabilidad is a noun. It comes from portable / portar-related word formation and means portability.

It is an abstract noun ending in -dad, a very common ending in Spanish for nouns like:

• posibilidad = possibility
• utilidad = usefulness
• calidad = quality

So in this sentence, portabilidad is the subject: the thing being talked about.

Here móvil is acting like an adjective that describes what kind of portability we mean: mobile portability.

In Spanish, adjectives often come after the noun, especially when they are classifying or specifying a type.

• portabilidad móvil = mobile portability
• compare with telefonía móvil = mobile telephony

So this is a normal word order in Spanish.

In this sentence, móvil is best understood as an adjective modifying portabilidad.

However, in everyday Spanish, móvil can also be a noun meaning mobile phone:

• Mi móvil = my mobile phone

But in la portabilidad móvil, it is not being used that way. It describes the type of portability, usually in the telecommunications sense.

Spanish usually uses ser with posible.

• es posible = it is possible

That is because posible expresses a general quality or condition, not a temporary physical state in the usual estar sense.

So:

• La portabilidad móvil es posible. = Mobile number portability is possible.

Using está posible would sound unnatural here.

Because the structure is different. In this sentence, Spanish makes la portabilidad móvil the subject directly:

• La portabilidad móvil = the subject
• es posible = is possible

So the sentence literally works like:

• Mobile portability is possible

Spanish often does not need a dummy subject like English it.

Yes, that is grammatically possible, but it sounds more marked or formal.

• La portabilidad móvil es posible. = the neutral, straightforward version
• Es posible la portabilidad móvil. = more emphasis on possible

In normal usage, the original sentence is the more natural default.

Because not all Spanish adjectives change form for gender.

Some adjectives have different masculine and feminine forms:

• alto / alta
• claro / clara

But others stay the same:

• posible
• interesante
• difícil

So you say:

• La portabilidad es posible
• El cambio es posible

The adjective stays posible in both cases.

A helpful approximate pronunciation is:

la por-ta-bi-li-DAD MO-bil es po-SI-ble

A few key points:

• portabilidad is stressed on the last syllable: -dad
• móvil is stressed on the first syllable because of the written accent: MÓ-vil
• posible is stressed on si: po-SI-ble

In Spain, v and b are pronounced very similarly.

In Spain, portabilidad móvil usually refers to mobile number portability: changing mobile operator while keeping your phone number.

So although the learner may already know the general meaning, this phrase often has a specific telecom meaning in real life, especially in ads, contracts, and customer service language.

Normally, no. That sounds unnatural in standard Spanish.

Spanish often uses the definite article with abstract nouns when speaking generally:

• La vida es corta.
• La educación es importante.
• La portabilidad móvil es posible.

So la is the natural choice here.

Using es posible makes it sound like a general statement of possibility or fact.

It does not strongly emphasize time; it simply states that this kind of portability can be done.

If you wanted to make it more time-specific, you might say things like:

• Ahora la portabilidad móvil es posible. = Now mobile portability is possible.
• Ya es posible la portabilidad móvil. = Mobile portability is now possible.

But the original sentence is a plain general statement.