Hun beskytter hjertet.

• Hun = she
• beskytter = protects
• hjertet = the heart

So the sentence structure is very straightforward: subject + verb + object.

Because hjertet is the definite form, meaning the heart.

In Danish, the definite article is usually added to the end of the noun instead of being a separate word in front.

• et hjerte = a heart
• hjertet = the heart

So the -et ending here shows that hjerte is a neuter noun.

You can tell because its indefinite article is et:

• et hjerte = a heart

For most Danish nouns, the definite ending depends on the gender:

• common gender nouns often take -en
• neuter nouns often take -et

So:

• et hjerte → hjertet

beskytter is the present tense form of the verb at beskytte.

• at beskytte = to protect
• beskytter = protects / is protecting

In Danish, the present tense often ends in -r.

Examples:

• jeg beskytter = I protect / am protecting
• hun beskytter = she protects / is protecting

It can mean both, depending on context.

Danish often uses the simple present where English might use either:

• protects
• is protecting

So Hun beskytter hjertet could mean:

• She protects the heart
• She is protecting the heart

Usually the surrounding context tells you which sounds more natural.

Because Danish usually attaches the to the noun as a suffix.

Instead of saying something like the heart with a separate article, Danish normally says:

• hjertet

That already includes the meaning of the.

A separate definite word like det is used in some other constructions, especially with adjectives:

• hjertet = the heart
• det røde hjerte = the red heart

Yes. This is the normal basic pattern:

• Hun = subject
• beskytter = verb
• hjertet = object

So: subject + verb + object

That is the standard word order in a simple main clause.

Danish also has the verb-second rule in main clauses, so if another element comes first, the verb still stays in second position:

• Hun beskytter hjertet.
• I dag beskytter hun hjertet. = Today she protects the heart.

In this sentence, hun means she.

It is the third-person singular pronoun used for a female person, and sometimes for a female animal if relevant.

Compare:

• hun = she
• han = he
• den/det = it in many contexts

So here, hun clearly identifies the subject as female.

A rough English-friendly guide would be something like:

• Hun ≈ hoon
• beskytter ≈ beh-SKIT-er or beh-SKUH-tər depending on how simplified you want it
• hjertet ≈ something like YER-det

A few notes:

• The hj in hjerte is not pronounced like English hj. It starts more like a y sound.
• Danish pronunciation is often less phonetic than spelling suggests.
• The vowels are especially important and can be tricky for English speakers.

If you want to sound natural, it is best to hear native audio and imitate it.

Because beskytter is a finite verb in the present tense, not the infinitive.

Compare:

• at beskytte = to protect
• beskytter = protects / is protecting

In a normal statement, Danish uses the conjugated verb:

• Hun beskytter hjertet.

You would only use at beskytte in contexts like:

• Det er vigtigt at beskytte hjertet. = It is important to protect the heart.

Yes. Like English heart, Danish hjerte can be used both:

• literally, for the organ
• figuratively, for emotions, love, courage, or kindness

So without context, hjertet could refer to:

• the actual heart in the body
• the symbolic heart

You add ikke after the verb:

• Hun beskytter ikke hjertet. = She does not protect the heart.

That placement is very common in Danish main clauses:

• subject + verb + ikke
  • object

You would use the indefinite form:

• et hjerte = a heart

So:

• Hun beskytter et hjerte. = She protects a heart

Compare:

• hjerte = heart
• et hjerte = a heart
• hjertet = the heart

No, much less than in English.

In Danish, the present tense form stays the same for all subjects:

• jeg beskytter = I protect
• du beskytter = you protect
• han beskytter = he protects
• hun beskytter = she protects
• vi beskytter = we protect

So you do not need a special verb ending just for she the way English adds -s in she protects. Danish uses beskytter for everyone in the present tense.