Mi hija pronuncia mejor la vocal abierta, pero todavía le cuesta una consonante final.

No. In Spanish, vocal usually means vowel.

So:

• la vocal abierta = the open vowel
• una consonante final = a final consonant

This is a very common false friend for English speakers, because English vocal usually relates to the voice or singing, while Spanish vocal is the normal word for vowel.

Because abierta describes vocal, and vocal is feminine in Spanish.

So the adjective has to agree:

• la vocal abierta = feminine singular
• el sonido abierto = masculine singular
• las vocales abiertas = feminine plural

This is standard adjective agreement in Spanish.

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

So:

• vocal abierta = open vowel
• consonante final = final consonant

This is the most natural order here. Spanish can sometimes place adjectives before the noun, but that usually changes the tone or meaning. In this sentence, the normal order is noun + adjective.

Here mejor means better, and it modifies the verb pronuncia.

• pronuncia mejor = pronounces better

Think of it as the comparative form of bien:

• bien = well
• mejor = better

So Spanish says:

• Pronuncia bien = She pronounces it well.
• Pronuncia mejor = She pronounces it better.

English speakers sometimes expect something more literal, but mejor is exactly the normal word here.

Because they do not point to the same level of specificity.

• la vocal abierta suggests a specific vowel sound or a known category already being discussed.
• una consonante final sounds less specific: a final consonant, one of that type.

So the contrast is:

• la = the, something identified or understood in context
• una = a/an, something not specifically identified

In a speech-therapy or pronunciation context, this is very natural: the speaker may be talking about one known vowel target, but just saying that final consonants are still hard.

Todavía here means still.

• pero todavía le cuesta... = but she still finds ... difficult

Yes, aún can often be used with the same meaning here:

• pero aún le cuesta...

Both are possible. In everyday Spanish, todavía is very common and clear.

This is one of the most important parts of the sentence.

Costar often works like gustar in this kind of structure. It means something like:

• to be hard for someone
• to cost someone effort
• to find something difficult

So:

• le cuesta = it is hard for her / she finds it difficult

The le is an indirect object pronoun, meaning to her.

You can think of the sentence as:

• Todavía le cuesta una consonante final
  = A final consonant is still difficult for her

In context, English would usually say She still has trouble with a final consonant or She still finds a final consonant difficult.

Sometimes learners expect a direct translation like she costs, but that is not how costar works here.

It can feel that way to an English speaker, yes.

In context, the full idea is something like:

• todavía le cuesta pronunciar una consonante final

Spanish often leaves things unsaid when the meaning is obvious from context. Since the sentence is already about pronunciation, pronunciar can be understood without being stated.

So the shorter version sounds natural, especially when the topic is already clear.

It means a consonant at the end, usually at the end of a word or syllable, depending on context.

For example, in pronunciation practice, final consonants can be difficult in words like:

• club
• verdad
• comer
• robot

So una consonante final refers to that final consonant sound. The adjective final simply means final / at the end.

Yes. That is also correct.

Adding a mi hija makes the person more explicit:

• A mi hija todavía le cuesta una consonante final.

The le usually stays, even when a mi hija is added. This is very normal in Spanish.

So you have:

• Mi hija... = My daughter...
• A mi hija le cuesta... = My daughter finds it difficult... / literally To my daughter, it is difficult...

Both are natural, but they are structured a little differently.

Hija is pronounced roughly like EE-ha, but with a Spanish j sound.

Important points:

• h is silent in Spanish
• j is a strong, raspy sound, not an English j

So:

• hija ≈ EE-kha / EE-ha depending on how you hear the Spanish j

Also, in much of Spain:

• pronuncia has a th-like sound for ci: pro-NUN-thya
• cuesta starts with kwe-
• todavía has the stress on -ví-

A rough pronunciation of the whole sentence in Peninsular Spanish is:

Mi I-ja pro-NUN-thya me-HOR la bo-KAL a-BYER-ta, PE-ro to-da-BEE-a le KWE-sta oo-na kon-so-NAN-te fi-NAL.

That is only an approximation, but it helps with the main sounds.