Virei o ás.

It comes from virar, not vir.

That is a very common point of confusion because the forms look similar. In this sentence:

• virar = the verb
• virei = I turned / I became, depending on context

If it were from vir (to come), the 1st person singular in the simple past would be vim, not virei.

So:

• vim = I came
• virei = I turned / I became

Virei is 1st person singular of the pretérito perfeito simples.

In practical terms, that means:

• I turned
• I became
• sometimes I flipped

depending on the context.

The ending -ei is typical for many -ar verbs in this tense:

• falei = I spoke
• olhei = I looked
• virei = I turned

Because Portuguese often leaves out the subject pronoun when the verb form already makes the subject clear.

Here, virei already tells you the subject is I. So eu is unnecessary unless you want emphasis or contrast.

Compare:

• Virei o ás. = normal, natural
• Eu virei o ás. = more emphatic, like I’m the one who turned/became the ace

This is very common in European Portuguese.

Because o is the definite article, so o ás means the ace or the expert / the star, depending on context.

Portuguese uses articles more often than English does. So where English might sometimes say just ace in certain expressions, Portuguese often prefers the article.

Examples:

• o ás de espadas = the ace of spades
• ele é um ás = he is an ace / he is brilliant at it

In this sentence, o ás is a noun phrase with a specific article, so it means the ace, not just ace in a general sense.

Because the word is spelled ás in Portuguese.

The accent helps show the stressed vowel and also distinguishes it from as, which is a very common word meaning things like the (feminine plural) or them, depending on the sentence.

So:

• ás = ace
• as = a grammatical word, not the same thing

For a learner, it is worth treating ás as a separate vocabulary item that simply has to be memorised with the accent.

Yes. Ás is a masculine noun, so it takes o in the singular:

• o ás
• um ás

This is something you just learn with the word. The ending -s does not tell you the gender, so the article is your clue.

Yes, it can be ambiguous without context.

Because virar has several meanings, Virei o ás could potentially be understood in different ways, such as:

• I turned/flipped the ace
• I became the ace / the top one

The exact meaning depends on the situation and the meaning already given to the learner.

A useful extra note for European Portuguese: if the intended meaning is to become, virar can be understood, but in some contexts it may sound more colloquial or less typical than alternatives such as tornar-se. So context matters a lot here.

A rough learner-friendly pronunciation would be:

vee-REI oo ASH

More precisely in European Portuguese:

• virei ≈ vi-REI
• o often sounds like u
• final -s in ás, at the end of the sentence, sounds like sh

So ás sounds roughly like ash.

The whole sentence is said smoothly, with the words linked together: virei o ás

It would normally go at the beginning:

• Eu virei o ás.

That is the most natural placement if you want emphasis.

You could also hear emphasis through intonation rather than by adding the pronoun. In neutral speech, though, Virei o ás. is perfectly normal.

Yes, but it would change the meaning.

• o ás = the ace
• um ás = an ace / a very skilled person

So if you say:

• Virei o ás. = I turned/became the ace
• Virei um ás. = I became an ace / I became really good

That difference between definite and indefinite article is important.