A sopa de beterraba ficou boa, mas a de abóbora ficou ainda melhor.

Ficou is the preterite form of ficar, and in this kind of sentence it often means turned out, came out, or ended up being.

So A sopa ... ficou boa means the soup turned out good after being made.

Compare:

• A sopa ficou boa. = The soup turned out good.
• A sopa estava boa. = The soup was good.
  This just describes its state.
• A sopa era boa. = The soup used to be good / was good in a more general or background sense.
  This is less natural here.

With food, ficar is very common in Brazilian Portuguese when talking about the final result of cooking.

Portuguese uses definite articles more often than English does.

Here, a sopa de beterraba means the beet soup or the beetroot soup, referring to a specific soup being discussed. In English, you might or might not say the, but in Portuguese the article is very natural.

Also, sopa is a feminine singular noun, so the article is a.

This is a very common kind of omission in Portuguese.

A de abóbora is short for:

a sopa de abóbora

The noun sopa is left out because it is already understood from the first part of the sentence.

So:

• a de abóbora = the pumpkin one
• literally: the pumpkin soup one

The a is there because it stands in for a sopa, which is feminine singular.

Here de means something like made with, of, or featuring that ingredient.

So:

• sopa de beterraba = beet/beetroot soup
• sopa de abóbora = pumpkin soup

This is a very common structure in Portuguese for foods:

• suco de laranja = orange juice
• bolo de chocolate = chocolate cake
• purê de batata = mashed potatoes / potato purée

You normally use de, not da, because you are naming the type of dish, not talking about one specific pumpkin or one specific beet.

Boa agrees with sopa, which is feminine singular:

• o bolo ficou bom
• a sopa ficou boa

But melhor is the irregular comparative form of bom/boa. In the singular, it does not change for gender:

• o bolo ficou melhor
• a sopa ficou melhor

In the plural, it becomes melhores:

• os bolos ficaram melhores
• as sopas ficaram melhores

So the contrast is:

• positive adjective: bom / boa
• comparative: melhor

Here ainda works as an intensifier, so ainda melhor means even better.

So the sentence says that the beet soup was good, but the pumpkin soup was even better.

This is a very common pattern:

• ainda mais = even more
• ainda pior = even worse
• ainda melhor = even better

Be careful: ainda can also mean still in other contexts, but here it means even.

Normally, no.

Portuguese usually uses the irregular comparative:

• bom / boa → melhor
• mau / má → pior
• grande → maior
• pequeno → menor

So the natural sentence is:

ficou ainda melhor

not

ficou ainda mais boa

You may occasionally hear mais bom/mais boa in very specific contexts or informal speech, but for learners, melhor is the correct and safest choice.

It is repeated for clarity and balance:

A sopa de beterraba ficou boa, mas a de abóbora ficou ainda melhor.

This sounds complete and natural.

Portuguese can sometimes omit repeated words, but in this sentence repeating ficou is the most standard and clear option. It helps keep the comparison neat:

• first soup: ficou boa
• second soup: ficou ainda melhor

Yes, both are possible.

• ainda melhor
• melhor ainda

Both can mean even better.

In this sentence, ainda melhor is very natural and probably a little more neutral.
Melhor ainda can sound slightly more emphatic, depending on context and intonation.

So both are acceptable, but the original version is perfectly standard.

This is a very common confusion for learners.

• mas = but
• mais = more

In your sentence, mas introduces a contrast:

...ficou boa, mas a de abóbora ficou ainda melhor.

That means ...was good, but the pumpkin one was even better.

Examples:

• Quero café, mas sem açúcar. = I want coffee, but without sugar.
• Quero mais café. = I want more coffee.

In many Brazilian accents, mas and mais can sound quite similar, so context matters a lot.

A simple pronunciation guide:

• beterraba → beh-teh-HAH-ba
  The stress is on ra.
• abóbora → a-BO-bo-ra
  The stress is on the first bó syllable.

And a few other words from the sentence:

• sopa → SO-pa
• ficou → fee-KOH
• boa → roughly BO-a
• melhor → roughly meh-LYOR in many Brazilian accents

The exact sound of r in Brazilian Portuguese varies by region, but the stress pattern above will already help a lot.