Seus comentários me ajudaram muito, então vou reescrever duas partes e melhorar a ortografia.

In Brazilian Portuguese, seu/sua/seus/suas is very commonly used for your, especially when speaking to someone as você.

• seus comentários = your comments
• teus comentários would match tu, not você

Since most of Brazil uses você much more than tu in everyday speech, seus sounds very natural here.

One extra note: seu can also mean his/her/their, so context matters.

Both are possible:

• Seus comentários
• Os seus comentários

In Brazilian Portuguese, possessives often appear without the article, especially in neutral, natural writing like this. Adding os is not wrong, but it can sound a little more explicit or formal depending on context.

So Seus comentários is completely normal.

Because the subject is comentários, which is plural.

• comentário → singular
• comentários → plural

So the verb must also be plural:

• Seu comentário me ajudou muito. = Your comment helped me a lot.
• Seus comentários me ajudaram muito. = Your comments helped me a lot.

Me is the object pronoun meaning me.

So:

• ajudaram = helped
• me ajudaram = helped me

Portuguese often places object pronouns before the verb in normal Brazilian usage, so me ajudaram is the most natural order here.

Ajudaram is the preterite, used for a completed action in the past.

Here, the speaker is referring to a finished event: the comments helped, and as a result, the speaker will now rewrite and improve the text.

So me ajudaram muito means something like:

• helped me a lot
• were very helpful to me

It presents the help as a completed fact.

Because muito here is an adverb, not an adjective.

It modifies the verb ajudaram:

• ajudaram muito = helped a lot

When muito is an adverb, it does not change for gender or number.

Compare:

• muito útil = very useful
• ajudaram muito = helped a lot

But as an adjective, it would agree:

• muitos comentários = many comments

Here então means so, therefore, or in that case.

It connects the two ideas:

1. Your comments helped me a lot
2. So I’m going to rewrite two parts and improve the spelling

So então shows consequence or result.

In Brazilian Portuguese, ir + infinitive is extremely common for talking about the future.

• vou reescrever = I’m going to rewrite
• reescreverei = I will rewrite

Both are correct, but vou reescrever sounds more natural and conversational in everyday Brazilian Portuguese. The simple future (reescreverei) often sounds more formal, literary, or less common in speech.

They are similar, but reescrever is more precise here.

• reescrever = to rewrite
• escrever de novo = to write again

Reescrever usually suggests revising or reformulating existing text, which fits this sentence better. The speaker is not just writing again from scratch, but revising parts of what was already written.

Because the speaker means two parts in a general, indefinite way.

• vou reescrever duas partes = I’m going to rewrite two parts

If the speaker said as duas partes, that would mean the two parts, implying two specific parts already clearly identified.

Without the article, it simply means two sections/parts of the text.

Portuguese often uses the definite article where English would not.

So:

• melhorar a ortografia = improve the spelling/orthography

The article a sounds natural here because the speaker is referring to the spelling of the text in question. In Portuguese, abstract nouns and general categories often take an article more readily than in English.

Almost, but ortografia is a little more formal or technical than everyday English spelling.

It refers to correct written form: accents, letter choice, standard written conventions, and so on.

In context, melhorar a ortografia is a very natural way to say:

• improve the spelling
• improve the orthography

In casual conversation, people might also talk about erros de português, erros de escrita, or corrigir a escrita, depending on what they mean.

The comma separates two clauses:

• Seus comentários me ajudaram muito
• então vou reescrever duas partes e melhorar a ortografia

This is natural punctuation because então is linking the first idea to the result or consequence in the second. In English, this works similarly to a comma before so in many sentences.

In Brazilian Portuguese, me ajudaram is much more natural.

Portuguese allows object pronouns in different positions, but Brazilian Portuguese strongly prefers pronouns before the verb in most everyday sentences:

• me ajudaram = normal, natural in Brazil
• ajudaram-me = correct, but more formal or more typical of European Portuguese or literary style

So for Brazilian Portuguese, me ajudaram is the best choice here.