Al final de la reunión, mi padre se quedó en silencio.

Al is the contraction of a + el.

• a = to / at
• el = the
• a + el = al

So al final literally means something like at the end.

A useful contrast:

• al final = at the end, in the end
• finalmente = finally
• por fin = finally / at last

In this sentence, Al final de la reunión means At the end of the meeting.

Because reunión is a feminine noun:

• la reunión = the meeting

So:

• al final de la reunión = at the end of the meeting

The structure is:

• el final de algo = the end of something

Examples:

• el final de la película = the end of the film
• el final del partido = the end of the match

Notice that with a masculine noun like partido, de + el = del.

Here, quedarse means to become or to end up in a state.

So se quedó en silencio means:

• he fell silent
• he became silent
• he remained in silence, depending on context

This is a very common use of quedarse:

• quedarse callado = to go quiet / stay quiet
• quedarse dormido = to fall asleep
• quedarse sorprendido = to be left surprised

So in this sentence, it is not about staying somewhere. It is about entering or remaining in a state.

Because the verb is quedarse, not just quedar.

These are different:

• quedar can mean to remain, to arrange, to be located, and other things
• quedarse often means to stay, to remain, or to become in a certain state

In this sentence, se is part of the verb quedarse.

Examples:

• Mi padre quedó en casa can sound like My father remained at home
• Mi padre se quedó en casa = My father stayed at home
• Mi padre se quedó en silencio = My father fell silent / remained silent

So the se is essential here.

Se quedó is the preterite, which presents the action as a completed event.

Here, the sentence describes a specific moment:

• At the end of the meeting, my father fell silent.

That sounds like a single completed change, so Spanish uses the preterite:

• se quedó

By contrast, se quedaba is the imperfect, which would suggest:

• a habitual action,
• background description,
• or an ongoing situation in the past.

Compare:

• Al final de la reunión, mi padre se quedó en silencio.
  = a completed event at that moment

• Cuando se enfadaba, mi padre se quedaba en silencio.
  = something he used to do repeatedly

Because that is usually the most natural English translation.

Literally, quedarse en silencio is close to:

• to remain in silence
• to stay in silence

But natural English often prefers:

• to fall silent
• to go quiet
• to become silent

Spanish commonly uses verbs like quedarse to express a change into a state, and English often uses more idiomatic expressions.

So:

• mi padre se quedó en silencio
  very naturally becomes
  my father fell silent

En silencio is a fixed and very common expression meaning in silence / silently / without speaking.

• se quedó en silencio = he fell silent / remained silent

Other options are possible, but they are slightly different:

• se quedó callado = he went quiet / stayed quiet
• estaba callado = he was quiet
• silencioso usually describes something as silent or quiet, but it is less natural for a person in this exact structure

So en silencio works very well because it focuses on the state of silence itself.

Normally, se quedó en silencio is the natural choice.

Without se, quedó en silencio may be understood in some contexts, but it is much less standard for this meaning. For a learner, it is safest to use:

• quedarse en silencio
• quedarse callado

So:

• Mi padre se quedó en silencio = the normal phrasing

Think of quedarse here as the standard verb for becoming/staying silent.

Because Al final de la reunión is an introductory time expression.

Spanish often uses a comma after an opening phrase like this, especially when it sets the scene:

• Al final de la reunión, mi padre se quedó en silencio.

The comma helps separate:

• the time/background phrase from
• the main clause

You may sometimes see short introductory phrases without a comma, but with a phrase like this, the comma is very natural and standard.

Yes. Spanish word order is flexible.

The neutral version is:

• Al final de la reunión, mi padre se quedó en silencio.

But you could also say:

• Mi padre se quedó en silencio al final de la reunión.

Both are correct. The difference is mostly one of focus:

• Al final de la reunión... puts the time frame first
• Mi padre... puts the subject first

Spanish often moves elements around for emphasis or style more freely than English.

Because Spanish normally uses a possessive with family members when you mean my father, your sister, etc.

• mi padre = my father
• tu madre = your mother

In some contexts, Spanish can use the definite article with family members, especially in certain regional or stylistic uses, but the standard and straightforward form here is:

• mi padre

So this sentence is completely normal and natural.

Yes, and it is a very useful alternative.

• guardó silencio = he kept silent / he remained silent
• se quedó en silencio = he fell silent / became silent / remained silent

The nuance is slightly different:

• se quedó en silencio often suggests a change into silence
• guardó silencio can sound a bit more formal or deliberate, as if the person kept silent

So both are correct, but they are not always identical in tone.

Reunión is pronounced approximately reh-oo-NYON.

The written accent on -ón shows that the stress falls on the last syllable:

• reu-nión

Without the accent mark, Spanish stress rules would suggest a different pronunciation, so the accent is needed.

Also, the ió combination here forms part of the stressed final syllable, and the n at the end is normal for many nouns of this type:

• reunión
• conversación
• decisión

The accent mark is important both for pronunciation and correct spelling.