Slunce jí svítí do tváře.

The subject is Slunce.

It is in the nominative singular and means the sun. The verb svítí is 3rd person singular, so it agrees with slunce.

Because Czech uses case endings, you can identify the subject by form, not just by position.

Here jí means to her and it is dative singular of ona (she).

In this sentence, it marks the person affected by the action: Slunce jí svítí do tváře = the sun is shining at her / into her face.

So jí is not the direct object. It is more like an indirect object or an affected person.

Because they are different forms:

• jí = to her / of her
• ji = her as a direct object

In this sentence, Czech needs the dative, so jí is correct.

Compare:

• Vidím ji. = I see her.
• Slunce jí svítí do tváře. = The sun is shining into her face.

So the long í matters.

Because the preposition do requires the genitive case.

The dictionary form is tvář (face), but after do it becomes:

• tvář = nominative
• tváře = genitive singular

So:

• do tváře = into the face

This is a very common Czech pattern:
do + genitive.

Because Czech often uses a dative pronoun instead of a possessive adjective when talking about body parts, especially when the possessor is obvious.

So Czech prefers:

• Slunce jí svítí do tváře.

rather than the more explicit:

• Slunce svítí do její tváře.

The first version sounds more natural.

This is similar to other Czech patterns:

• Bolí mě hlava. = My head hurts.
  Literally: The head hurts me.
• Dívá se mi do očí. = He is looking into my eyes.

Yes, literally it is into the face.

In Czech, do + genitive is often used when something is directed toward the face, eyes, mouth, and so on. With light, wind, smoke, rain, etc., this is very natural.

English usually says:

• in her face
• in her eyes

rather than a literal into her face, but the Czech structure is normal.

Because short pronoun forms in Czech often go in second position in the sentence.

So jí naturally appears early:

• Slunce jí svítí do tváře.

This is a very typical Czech word-order pattern. Even though Czech word order is flexible, small pronouns often have preferred placement.

So this sentence sounds very natural and neutral.

Yes. Czech word order is flexible, and different orders change the emphasis or style more than the basic meaning.

For example:

• Slunce jí svítí do tváře. = neutral
• Jí svítí slunce do tváře. = puts more focus on her
• Do tváře jí svítí slunce. = more marked, possibly literary or descriptive

Because the cases show the grammatical roles, Czech does not rely on word order as much as English does.

Svítí is the present tense, 3rd person singular of svítit.

So it means:

• shines
• is shining

In this sentence it describes an ongoing situation, so the imperfective verb svítit is exactly what Czech normally uses.

Because Czech has no articles.

So slunce can mean:

• sun
• the sun

The exact meaning comes from context.

In this sentence, English naturally uses the sun, but Czech simply says slunce.

In this sentence, yes: jí refers to a female person.

By itself, jí is a form of ona (she), so here it means to her.

A learner may also meet jí in other contexts, so it can look ambiguous at first, but in this sentence the grammar makes the meaning clear: the sun is shining into her face.

Yes, it is very natural.

Czech commonly uses:

• svítit někomu do tváře
• svítit někomu do očí

These mean that light is shining toward someone’s face or eyes.

So this sentence sounds like normal, idiomatic Czech, not a word-for-word translation from English.