El papá llegó ayer.

Spanish often uses the definite article with family nouns when the person is already identifiable from context. So el papá can mean something like the dad or, in the right context, simply dad.

Useful comparisons:

• el papá = the dad / dad, when it is clear who is meant
• mi papá = my dad, more explicit
• Papá llegó ayer = also possible, especially when papá is used almost like a name

So Spanish does not always use a possessive like my where English often does.

Papá is more personal and affectionate, like dad.
Padre is more neutral or formal, like father.

So:

• papá = everyday, family use
• padre = more formal, neutral, or descriptive

A child or family member is much more likely to say papá than padre in normal conversation.

Llegó is the preterite form, third person singular, of llegar.

That means it describes a completed action in the past: the arrival happened and is finished.

Because the sentence includes ayer, a finished past time, the preterite is the normal tense here.

The accent mark shows both stress and meaning.

• llegó = he arrived / she arrived / it arrived
• llego = I arrive or I am arriving

So the accent is important. It is not optional spelling; it changes the form of the verb.

It also tells you to stress the last syllable: lle-GÓ.

The accent shows that the stress falls on the last syllable: pa-PÁ.

Without the accent, papa is a different word. In Spanish, that can mean pope. So papá and papa are not the same word.

The accent is therefore part of the correct spelling and helps distinguish meanings.

In most of Spain, ll in llegó is pronounced like the y in yes, so llegó sounds roughly like ye-GO.

A few details:

• ll is usually not pronounced like two English l sounds
• g before o is a hard g, like in go
• the stress is on the last syllable: lle-GÓ

Depending on the region, pronunciation can vary a bit, but ye-GO is a good practical guide for many learners.

Yes, if the context already makes it clear who arrived.

Spanish often leaves out subjects when they are understood. So:

• Llegó ayer = He/She arrived yesterday
• El papá llegó ayer = specifies that it was the father/dad

Spanish is much more comfortable than English with leaving the subject unstated when the listener can figure it out.

Yes. Spanish word order is flexible, especially with time expressions like ayer.

All of these are possible:

• El papá llegó ayer
• Ayer llegó el papá
• Llegó ayer el papá

The most neutral version is usually El papá llegó ayer.
Moving ayer changes the emphasis a little, but not the basic meaning.

Usually, no.

In El papá llegó ayer, papá is a common noun, so it stays lowercase.

You may see it capitalized when it is used like a name in direct address:

• Papá, ven aquí.

So:

• El papá llegó ayer = lowercase
• Papá, escucha = capitalized because it functions like a name

In Spain, both forms exist, but they are used differently.

With a finished time expression like ayer, the normal choice is the preterite:

• llegó ayer

The present perfect, ha llegado, is more natural when the time period is still connected to the present, for example:

• hoy
• esta semana
• esta mañana if the morning is still part of the current time frame

So with ayer, llegó is the standard choice.