A conclusão ficou curta, então vou reescrever a última frase.

Ficou curta means ended up being short or turned out short. It suggests a result: after writing or reviewing the conclusion, the speaker realizes it is too short.

• é curta = it is short as a general statement
• está curta = it is short right now, focusing on the current state
• ficou curta = it became / turned out short

In this sentence, ficou sounds very natural because the speaker is reacting to the finished conclusion.

Conclusão is a feminine singular noun, so it takes the feminine singular definite article a.

• o = masculine singular
• a = feminine singular
• os = masculine plural
• as = feminine plural

So:

• a conclusão = the conclusion

Many Portuguese nouns ending in -ão are masculine, but conclusão is feminine, so this is something you simply need to learn with the noun.

Because it agrees with conclusão, which is feminine.

• curto = masculine singular
• curta = feminine singular
• curtos = masculine plural
• curtas = feminine plural

Since conclusão is feminine singular, the adjective must also be feminine singular:

• A conclusão ficou curta.

Here, curta means too short or not long enough in context.

Portuguese often does not need to say too explicitly when the situation already makes that clear. So:

• A conclusão ficou curta literally = The conclusion turned out short
• natural meaning = The conclusion ended up too short

Então here means so, therefore, or in that case.

It connects the two ideas:

• A conclusão ficou curta = the conclusion was too short
• então vou reescrever a última frase = so I’m going to rewrite the last sentence

It is very common in spoken and written Portuguese.

Vou reescrever is the very common ir + infinitive future construction, equivalent to I’m going to rewrite.

Structure:

• vou = present of ir for eu
• reescrever = infinitive, to rewrite

So:

• vou reescrever = I’m going to rewrite

Portuguese also has a simple future:

• reescreverei = I will rewrite

But in everyday Brazilian Portuguese, vou reescrever is much more common and natural in speech.

Reescrever = re- + escrever

• escrever = to write
• reescrever = to rewrite

The prefix re- works a lot like English re-:

• fazer = to do
• refazer = to redo
• ler = to read
• reler = to reread

So reescrever literally means to write again.

Portuguese often uses the definite article where English might omit it.

• a última frase = the last sentence

Using the article makes it specific and natural. Without the article, it would sound less complete in this sentence.

In Portuguese, many adjectives can come after the noun, but some very common ones often come before it, especially words like:

• último/última = last
• primeiro/primeira = first
• próximo/próxima = next
• mesmo/mesma in some uses

So:

• a última frase = the last sentence

This is the normal order here.

Yes — this is a very common point of confusion.

In Portuguese:

• frase usually means sentence
• English phrase is often expressão or sometimes frase depending on context, but not always in the grammatical sense English learners expect

So in this sentence:

• a última frase = the last sentence

Not the last phrase in the usual English grammar sense.

Yes. Curto/curta can refer to length in many senses, including text, speech, time, or physical length.

Examples:

• um texto curto = a short text
• uma reunião curta = a short meeting
• uma saia curta = a short skirt

So a conclusão ficou curta is perfectly natural for writing.

The comma separates two related clauses:

• A conclusão ficou curta
• então vou reescrever a última frase

This is very normal punctuation in Portuguese when então is used as a connector meaning so or therefore.

Yes, you could, and it would still be understandable and natural.

The difference is small:

• ficou curta = it ended up short / turned out short
• está curta = it is short right now

In this context, ficou curta often sounds slightly better because it emphasizes the result of the writing.

Yes, but the nuance is slightly different.

• a última frase = the last sentence
• a frase final = the final sentence

These are often interchangeable, but a última frase is probably the most direct and natural wording here.

A rough pronunciation guide is:

a kon-kloo-ZOWN fee-KOH KOOR-ta, en-TOWN voh heh-ees-kreh-VER a OOL-chee-ma FRAH-zee

A few useful notes for Brazilian Portuguese:

• ão is a nasal sound
• ficou sounds like fee-KOH
• então has nasal ão
• última in Brazil often sounds like OOL-chee-ma
• frase usually sounds more like FRAH-zee in Brazilian Portuguese

This is only an approximation, but it can help at first.

Yes, it is completely natural.

It sounds like something someone might say while revising a piece of writing. The vocabulary, grammar, and word order are all standard and idiomatic in Brazilian Portuguese.