La guía habló con tanta sinceridad de su ciudad que hasta mi madre quiso volver a esa capital.

Here, la guía means the guide, and la tells you the guide is a woman.

The noun guía can refer to either a male or female person:

• el guía = a male guide
• la guía = a female guide

Also, guía can mean guidebook in other contexts, but in this sentence it clearly means a person because of habló.

Habló is the preterite, which presents the action as a completed event in the past.

So La guía habló... suggests a specific finished moment: the guide spoke, and that had a result.

If you said hablaba, that would sound more like background description or an ongoing past action:

• La guía hablaba con tanta sinceridad... = the guide was speaking so sincerely...

In this sentence, the speaker is focusing on the completed action and its consequence, so habló is the natural choice.

Because sinceridad is a noun, and with nouns Spanish uses tanto / tanta / tantos / tantas.

Here:

• sinceridad is feminine singular
• so you need tanta

Compare:

• tan sincera = so sincere → tan
  • adjective
• tan sinceramente = so sincerely → tan
  • adverb
• tanta sinceridad = so much sincerity / such sincerity → tanta
  • noun

So con tanta sinceridad is correct because sinceridad is a noun.

This is a very common Spanish pattern used to express result.

The structure is:

• tan / tanto / tanta / tantos / tantas + word + que + result

In this sentence:

• con tanta sinceridad ... que ... means something like with such sincerity ... that ...

So the idea is: the guide spoke with such sincerity that even the speaker’s mother wanted to return.

You can think of que here as introducing the consequence.

Yes. Hablar de means to talk about or to speak about.

So:

• habló de su ciudad = spoke about her city

That de belongs naturally with hablar when you say what the topic is.

You will often see:

• hablar de política
• hablar de un problema
• hablar de su ciudad

Yes, su can be ambiguous.

It can mean:

• his
• her
• its
• their
• your in formal singular usted

In this sentence, context tells us su ciudad refers to the guide’s city. So English would normally understand it as her city.

Spanish often leaves this kind of thing to context.

Hasta can mean until, but in this sentence it means even.

So:

• hasta mi madre = even my mother

This use adds emphasis and suggests surprise: if even my mother wanted to go back, the guide must have spoken very convincingly.

So hasta has at least these two common uses:

• hasta las cinco = until five
• hasta mi madre = even my mother

Quiso is the preterite of querer, and here it refers to a specific reaction at that moment.

So the meaning is roughly:

• the guide spoke like that, and as a result, my mother wanted / felt like / was moved to want to return

If you used quería, it would sound more like an ongoing state or background feeling:

• mi madre quería volver = my mother wanted to return / used to want to return

In many contexts, the preterite quiso can suggest a more immediate, concrete reaction than quería.

Because volver takes a before a destination.

So:

• volver a Madrid
• volver a casa
• volver a esa capital

That a is the normal preposition used with movement toward a place.

Be careful not to confuse this with another structure:

• volver a + infinitive = to do something again
  Example: volver a intentarlo = try again

In your sentence, volver a esa capital means to return to that capital.

Because esa is a demonstrative determiner, and it replaces the article.

So you say:

• esa capital not
• la esa capital

Just like in English:

• that city not
• the that city

Also, esa points to something already identified or mentally distant from the speaker. In this sentence, it refers back to the city already mentioned, now described as a capital.

Yes, here capital is feminine because it means capital city:

• la capital
• esa capital

This is worth noticing because capital can also be masculine in other meanings, especially in more formal or economic language:

• el capital = capital, wealth, funds

So the gender depends on the meaning:

• la capital = the capital city
• el capital = capital in the financial sense

Yes. Both are grammatical, but they are built differently:

• habló con tanta sinceridad = literally spoke with so much sincerity
• habló tan sinceramente = spoke so sincerely

The meaning is very similar. The version in your sentence uses a noun phrase:

• tanta sinceridad

The alternative uses an adverb:

• tan sinceramente

Spanish often allows both kinds of expression.

The word order is very natural as written:

• La guía habló con tanta sinceridad de su ciudad que...

Here, de su ciudad is the topic of what she spoke about, and con tanta sinceridad describes how she spoke.

You could move things around for emphasis, but the original order sounds smooth and standard. For example:

• La guía habló de su ciudad con tanta sinceridad que...

That is also correct and very natural. The difference is mostly one of rhythm and emphasis, not basic meaning.

They have accent marks for different reasons.

Guía

• The accent on í shows that guí-a is pronounced in two syllables.
• Without the accent, the spelling would suggest a different vowel grouping.

Habló

• The accent shows stress on the last syllable: ha-BLÓ
• It also helps distinguish it from hablo, which means I speak in the present:
  • hablo = I speak
  • habló = he/she spoke

So the accents are important both for pronunciation and for meaning.