Ontem torci o pulso e bati com o cotovelo na mesa.

Portuguese often drops the subject pronoun when the verb ending already makes the subject clear.

Here, torci and bati both clearly mean I ... because they are 1st person singular forms. So eu is unnecessary.

You could say Ontem eu torci o pulso e bati com o cotovelo na mesa, but that usually adds emphasis, contrast, or clarity. In neutral speech, leaving out eu is more natural.

They are both in the pretérito perfeito, which is the normal simple past for completed actions.

That fits well with ontem, because the sentence is talking about two finished events that happened yesterday.

So the structure is basically:

• torci = I twisted / I sprained
• bati = I hit / I banged

Because the verb is torcer, and the eu form in the simple past is torci.

This is the normal result of the verb stem plus the ending:

• torcer → torci

Torcei is not the correct form here.

A quick comparison:

• eu torci
• tu torceste
• ele/ela/você torceu
• nós torcemos
• vocês/eles/elas torceram

So torci is simply the correct past form for I.

With body parts, Portuguese usually uses the definite article rather than a possessive, when it is already obvious whose body part it is.

So:

• torci o pulso
• bati com o cotovelo

sound natural in Portuguese, even though English normally says my wrist and my elbow.

You can use the possessive for emphasis or contrast:

• torci o meu pulso, não o teu

But in an ordinary sentence, the article alone is the usual choice.

Because the meaning comes from the context and the verb used.

The noun pulso can mean:

• wrist
• pulse

But with torcer in this kind of sentence, it is understood as the body part, not the heartbeat. You can twist or sprain a wrist, but not a pulse.

So the context makes the intended meaning clear.

After bater, Portuguese often uses com to introduce the thing or body part that made contact.

So bati com o cotovelo means that the elbow was the part that hit something.

This structure is very common for accidental bumps:

• bati com a cabeça na porta
• bati com o joelho na cadeira
• bati com o cotovelo na mesa

For an English speaker, it can feel a bit unusual, because English often makes the body part the direct object. Portuguese often prefers this bater com + body part + em/na/no + place/object pattern.

Na is a contraction of:

• em
  • a = na

Here:

• mesa is a feminine noun
• so em a mesa becomes na mesa

This kind of contraction is very common in Portuguese:

• no = em + o
• na = em + a
• nos = em + os
• nas = em + as

It can go in other places too.

Ontem at the beginning is very natural because it sets the time right away:

• Ontem torci o pulso e bati com o cotovelo na mesa.

But you could also say:

• Torci o pulso ontem e bati com o cotovelo na mesa.
• Torci ontem o pulso e bati com o cotovelo na mesa.
  This is possible, but less neutral in everyday speech.

So the beginning position is common and natural, but not the only option.

Yes, in normal context it usually sounds like an accidental bump.

That is one reason this structure is so common with body parts. It often describes knocking, banging, or bumping yourself against something.

If you wanted to make the action sound clearly deliberate, you would usually add more context or use wording that makes intention obvious.

You may hear some variation, but bati com o cotovelo na mesa is the more natural and idiomatic pattern for this kind of accidental contact.

Using com is especially common when talking about bumping a body part against something.

So for a learner, bater com + body part + na/no + object is a very good pattern to remember.

A rough European Portuguese pronunciation guide would be:

• Ontem → roughly ON-tãyng
• torci → roughly tur-SEE
• o pulso → roughly u POOL-su
• e bati → roughly i buh-TEE
• com o cotovelo → roughly kõ u cu-tu-VEH-lu
• na mesa → roughly nuh MEH-zuh

A few useful pronunciation notes for European Portuguese:

• Unstressed o often sounds like u
• Unstressed final o is usually reduced
• em / en can create a nasal sound
• c before i in torci sounds like s

So the sentence may sound more compressed than an English speaker expects, especially in fast speech.