Con el tiempo, mi hermana se va poniendo más segura al hablar en público.

Con el tiempo means with time / over time / as time goes by. It sets the idea that the change is gradual, not immediate.

In this sentence, it tells you that the sister is becoming more confident little by little.

You could also hear similar expressions such as:

• Con el paso del tiempo
• Poco a poco
• Cada vez más

All of them can suggest development over time, but con el tiempo is a very natural general opener here.

Because irse + gerundio adds the idea of a gradual process.

• Se pone más segura = she becomes more confident
• Se va poniendo más segura = she is gradually becoming more confident

So va poniendo is not just about the result. It highlights the change as it develops step by step.

This is a very common Spanish pattern:

• va mejorando = is gradually improving
• voy entendiendo = I’m gradually starting to understand
• se fueron acostumbrando = they gradually got used to it

The verb here is ponerse, not just poner.

• poner usually means to put
• ponerse can mean to become, especially with states or conditions

So:

• pone el libro en la mesa = he/she puts the book on the table
• se pone nerviosa = she gets nervous
• se pone contenta = she becomes happy

In your sentence, se va poniendo más segura means she is gradually becoming more confident.

The se is part of the pronominal verb ponerse and should not be translated word for word.

Yes. Se va poniendo and va poniéndose are both correct.

With a conjugated verb plus a gerund, the pronoun can often go:

• before the conjugated verb: se va poniendo
• attached to the gerund: va poniéndose

In everyday usage, se va poniendo is often a little more common and can feel slightly more natural to many speakers, but both are standard.

Because segura agrees with mi hermana, which is feminine singular.

Spanish adjectives usually agree in gender and number with the noun they describe:

• mi hermano está seguro
• mi hermana está segura
• mis hermanas están seguras

Here, segura describes the sister, so it must be feminine singular.

Here it means confident, not safe.

The adjective seguro/a can mean different things depending on context:

• Estoy seguro = I’m sure / certain
• Es un lugar seguro = It’s a safe place
• Se siente más segura al hablar = She feels more confident when speaking

In this sentence, because it is about speaking in public, the meaning is clearly confident.

Because Spanish comparatives use this structure:

• más + adjective
• menos + adjective

So:

• más segura = more confident
• más rápido = faster
• menos difícil = less difficult

You do not use de before the adjective in this pattern.

Al + infinitive often means when, upon, or while doing something, depending on context.

So:

• al hablar en público = when speaking in public / when she speaks in public

It is a very common structure in Spanish. For example:

• Al entrar, saludó a todos = On entering / When he entered, he greeted everyone
• Al estudiar, escucho música = When I study, I listen to music

In your sentence, it tells you in what situation she is becoming more confident: when speaking in public.

Yes, you could, and the meaning would be very similar.

• al hablar en público
• cuando habla en público

Both can mean when speaking in public.

The difference is mainly stylistic:

• al hablar is a bit more compact and slightly more formal or written-sounding
• cuando habla feels a bit more explicit and conversational

So both are correct, but the original version is very natural.

En público is the standard expression for in public or before an audience.

It does not have to mean literally standing in a public place. It can simply mean speaking in front of other people.

Examples:

• Hablar en público = to speak in public
• Cantar en público = to sing in public

It is the normal collocation, so it is best learned as a set phrase: hablar en público.

It is not absolutely necessary, but it is very common.

Con el tiempo is an introductory phrase, and Spanish often places a comma after that kind of opener:

• Con el tiempo, todo cambia
• En general, prefiero quedarme en casa
• Por suerte, llegamos a tiempo

Without the comma, the sentence is still understandable:

• Con el tiempo mi hermana se va poniendo más segura al hablar en público

But the comma helps readability and sounds more polished in writing.

Yes. Spanish often drops subject pronouns and even noun subjects when the context is clear.

So you could say:

• Con el tiempo, se va poniendo más segura al hablar en público

If everyone already knows you are talking about your sister, this is fine.

However, keeping mi hermana makes the sentence clearer and gives it more focus.

Yes, very well.

You could say:

• Con el tiempo, mi hermana se va poniendo cada vez más segura al hablar en público

Cada vez más means more and more, so it reinforces the idea of steady progress.

Compare:

• más segura = more confident
• cada vez más segura = more and more confident

The second version sounds even more explicitly gradual.