Tiene una sonrisa linda.

Because Spanish often omits subject pronouns when they are not needed.

So instead of saying:

• Él tiene una sonrisa linda
• Ella tiene una sonrisa linda

Spanish very naturally says just:

• Tiene una sonrisa linda

The verb tiene already tells you it is third person singular, so the subject is usually understood from context.

It could mean:

• he has
• she has
• you have (formal usted)

You only add él, ella, or usted if you want to clarify or emphasize the subject.

Tiene is the third-person singular form of tener (to have).

In this sentence, it can mean:

• he has
• she has
• you have (formal)

So by itself, tiene does not tell you whether the subject is male, female, or formal you. Only the context does that.

For example:

• María tiene una sonrisa linda. = María has a lovely smile.
• El profesor tiene una sonrisa linda. = The teacher has a lovely smile.
• Speaking politely to someone: Tiene una sonrisa linda. = You have a lovely smile.

Spanish often uses tener (to have) in places where English also uses have:

• Tiene una sonrisa linda. = He/She has a lovely smile.

That is the most natural structure here.

You could also say:

• Su sonrisa es linda. = His/Her smile is lovely.

But that shifts the focus a little.

• Tiene una sonrisa linda focuses on the person as someone who has that smile.
• Su sonrisa es linda focuses more directly on the smile itself.

Both are possible, but tiene una sonrisa linda is very natural.

Because sonrisa is a singular countable noun, and here it is being presented as a smile:

• una sonrisa = a smile

So:

• Tiene una sonrisa linda = literally He/She has a lovely smile

In English, we also say a lovely smile, so this matches quite well.

In Spanish, adjectives usually come after the noun.

So:

• una sonrisa linda = a lovely smile

That is a normal noun + adjective order.

You may also sometimes see:

• una linda sonrisa

This is possible, but putting the adjective before the noun often makes it sound a bit more subjective, expressive, or literary.

So the difference is roughly:

• una sonrisa linda = neutral, standard description
• una linda sonrisa = a bit more expressive or stylistic

It is understood in Spain, but it is often felt to be more common in Latin America.

In Spain, people may more often say:

• bonita
• muy bonita
• preciosa
• sometimes agradable, depending on the meaning

So in Spain, many speakers might naturally prefer:

• Tiene una sonrisa bonita.

That said, linda is absolutely understandable, and some speakers do use it. It just may not sound as typically Peninsular as bonita.

They are very close in meaning, and in many contexts both can mean pretty, lovely, or nice-looking.

For this sentence:

• una sonrisa linda
• una sonrisa bonita

Both work.

A rough nuance is:

• bonita = pretty, attractive, nice-looking
• linda = lovely, pretty, sweet, charming

But the difference is often small, and usage depends a lot on region and personal style.

For Spanish from Spain, bonita is generally the safer and more neutral everyday choice.

Because adjectives must agree in gender and number with the noun they describe.

Here, the noun is:

• sonrisa = smile

Sonrisa is feminine singular, so the adjective must also be feminine singular:

• linda

Compare:

• un gesto lindo = a lovely gesture
• una sonrisa linda = a lovely smile

So the ending changes to match the noun.

Yes. Sonrisa is a feminine noun:

• la sonrisa
• una sonrisa

That is why the adjective must also be feminine:

• una sonrisa linda
• una sonrisa bonita

Even though many nouns ending in -a are feminine, it is still best to learn each noun with its article:

• la sonrisa

Usually, no—not if you are speaking informally.

If you are talking to one person informally (tú), you would say:

• Tienes una sonrisa linda.

If you are talking to one person formally (usted), then you use:

• Tiene una sonrisa linda.

So:

• tienes = you have (informal singular)
• tiene = he/she has or you have (formal singular)

This is a very common point of confusion for English speakers.

Yes, it can.

Saying someone has a lovely smile is often a compliment, and depending on tone and context, it may sound:

• friendly
• warm
• affectionate
• flirtatious

So if you say this directly to someone, it may come across as more personal than a neutral observation.

If you are just describing someone to another person, it is less likely to sound flirtatious:

• María tiene una sonrisa linda.

A simple pronunciation guide is:

• Tiene → TYEH-neh
• una → OO-nah
• sonrisa → son-REE-sah
• linda → LEEN-dah

So the full sentence is roughly:

TYEH-neh OO-nah son-REE-sah LEEN-dah

In Spain, depending on accent, pronunciation details may vary slightly, but this guide is a good starting point.

Yes, absolutely.

Adding muy intensifies the adjective:

• Tiene una sonrisa muy linda. = He/She has a very lovely smile.

That is completely natural.

You could also say:

• Tiene una sonrisa muy bonita.

In Spain, muy bonita may sound more idiomatic than muy linda, but both are understandable.