Calhou o ás.

Calhou is the 3rd person singular of the verb calhar in the pretérito perfeito simples.

So grammatically it means something like:

• it came up
• it fell by chance
• it turned out

In this sentence, the singular form matches o ás.

Calhar adds the idea of chance, luck, or random outcome.

So in a sentence like Calhou o ás, the feeling is not just that the ace appeared, but that it came up by chance or was the card that turned up.

This verb is very natural in situations involving:

• cards
• draws
• lotteries
• random results
• things that happen by coincidence

Because Portuguese often places the subject after the verb when presenting a result or announcing what came up.

So Calhou o ás sounds natural in the sense of:

• up came the ace
• the ace was the one that turned up

This post-verbal order is common with verbs that introduce an event or outcome.

A more neutral subject + verb order, O ás calhou, is grammatically possible in some contexts, but it would sound less natural here.

Here, o ás is most naturally understood as the subject, even though it comes after the verb.

That is very common in Portuguese.

A useful comparison:

• Calhou o ás. = The ace came up.
• Calhou-lhe o ás. = He/She got the ace.

In the second sentence, lhe shows the person affected, while o ás is still the thing that came up.

Portuguese often uses articles with nouns in places where English might not.

With card names, o is very normal:

• o ás
• o rei
• a dama

So o ás means the ace, referring to the card that came up.

If you said um ás, that would mean an ace, which is possible, but it changes the focus slightly:

• o ás = the specific ace that turned up
• um ás = an ace, one ace, without the same definite feel

Ás has an acute accent because it is a stressed monosyllable and follows Portuguese spelling rules.

The accent also helps distinguish it from as, which is a very common unstressed word, such as:

• the feminine plural article
• a pronoun

So:

• ás = ace
• as = the / them, depending on context

Ás is masculine, which is why the sentence has o ás.

Its plural is ases.

Examples:

• o ás
• os ases

A rough European Portuguese pronunciation is:

• calhou ≈ kɐ-LYOH
• o ás ≈ u ASH

A few useful points:

• lh is a palatal sound, roughly like ly in million, though not exactly the same.
• ás is stressed on the only syllable.
• Final s in European Portuguese often sounds like sh, so ás sounds roughly like ash, but with a purer a vowel.

In connected speech, o ás may flow together smoothly, so you may hear something close to wásh after the verb.

Yes. Calhar is very common in Portugal.

It is used not only for cards or draws, but also for:

• coincidences
• things that happen to be the case
• things that suit the moment

Very common examples include:

• Calhou bem. = It worked out well.
• Calhou estar lá. = He/She happened to be there.
• Se calhar... = maybe / perhaps

So in Calhou o ás, you are seeing a very typical European Portuguese verb used in a natural way.