La conductora frenó en seco al ver al peatón.

Conductora is the feminine form of conductor, so it tells you the driver is a woman.

• el conductor = the male driver
• la conductora = the female driver

In this sentence, Spanish makes the driver's gender explicit. In English, the driver does not usually show gender.

Also, conductor/conductora can mean other things in some contexts, but here it clearly means driver.

Frenó is the preterite form of frenar for él/ella/usted:

• frenar = to brake
• frenó = he/she braked

The preterite is used because this is a completed action: she braked at a specific moment.

Compare:

• frenó = she braked / she slammed on the brakes
• frenaba = she was braking / she used to brake

Here, the sentence describes one sudden event, so frenó is the natural choice.

En seco is an idiomatic expression meaning abruptly, suddenly, or to a dead stop.

So frenó en seco means something like:

• she braked suddenly
• she stopped short
• she slammed on the brakes

It does not literally mean anything about being dry in this sentence, even though seco on its own usually means dry.

Al ver means upon seeing, when she saw, or on seeing.

It is made from:

• a + el = al
• ver = to see

This structure, al + infinitive, is very common in Spanish and often expresses when, upon, or as soon as someone does something.

Examples:

• Al entrar, saludó. = Upon entering, he/she greeted everyone.
• Al oír el ruido, se asustó. = When he/she heard the noise, he/she got scared.

So in your sentence, al ver al peatón means when she saw the pedestrian.

That is the personal a.

In Spanish, when a direct object is a specific person (or sometimes a personified being), you usually put a before it.

So:

• ver al peatón = to see the pedestrian

Here:

• el peatón is a specific person
• so Spanish uses a
• a + el = al

Compare:

• Veo la casa. = I see the house.
  No personal a, because it is a thing.
• Veo al peatón. = I see the pedestrian.
  Personal a, because it is a person.

Because two different grammar points produce the same form al:

1. al ver

   • here al comes from a + el in the structure al + infinitive
   • it means when/upon

2. al peatón

   • here al comes from the personal a
     • el
   • it marks the pedestrian as a specific person being seen

So both are spelled al, but they are doing different jobs.

Peatón means pedestrian.

It refers to a person who is walking, especially in relation to traffic and roads.

So:

• el peatón = the pedestrian

The accent mark in peatón shows that the stress falls on the last syllable: pea-TÓN.

Yes. Spanish allows some flexibility in word order.

You could also say:

• Al ver al peatón, la conductora frenó en seco.

This means the same thing. In fact, this order may sound slightly more natural to some speakers because the cause comes first and the main action comes after.

The original sentence is also completely correct:

• La conductora frenó en seco al ver al peatón.

Spanish uses definite articles more often than English.

So Spanish naturally says:

• la conductora
• el peatón

English might say:

• the driver
• the pedestrian

But depending on context, English may also leave things less explicit. Spanish tends to include the article in many cases where English also would, and sometimes in cases where English would not.

Here, the articles help identify both people as specific participants in the situation.

Usually, no—not for this meaning.

The natural verb here is:

• frenar = to brake / to stop by braking

So:

• La conductora frenó. = The driver braked.

Se frenó can exist in some contexts, but it often sounds different in meaning or less natural here. For a driver actively stopping a vehicle, frenó is the normal choice.

If you want to make the car explicit, you could say:

• La conductora frenó el coche en seco al ver al peatón.

Not always. It depends on context.

Al + infinitive can often be translated as:

• when
• upon
• on
• after
• as soon as

In this sentence, likely translations include:

• When she saw the pedestrian, the driver braked suddenly.
• Upon seeing the pedestrian, the driver braked abruptly.

So al ver does not literally contain she or a past tense verb, but English often translates it that way because it sounds more natural.

By default, the understood subject of al + infinitive is normally the same subject as the main verb.

So in:

• La conductora frenó en seco al ver al peatón.

the person who saw the pedestrian is understood to be the driver.

In other words:

• the driver braked
• the driver saw the pedestrian

That is the normal interpretation unless the sentence makes a different subject clear in some other way.

A fairly literal breakdown is:

• La conductora = the female driver
• frenó = braked
• en seco = abruptly / to a dead stop
• al ver = upon seeing / when she saw
• al peatón = the pedestrian

So a close literal version would be:

The female driver braked abruptly upon seeing the pedestrian.

A more natural English translation would often be:

The driver slammed on the brakes when she saw the pedestrian.