Han kysser hånden hennes.

Because hånden is the definite form of hånd.

• hånd = hand
• hånden = the hand

In Norwegian, when a possessive comes after the noun, the noun is usually definite:

• hånden hennes = her hand
• literally: the hand her

So Han kysser hånden hennes follows a very common Norwegian pattern.

That is one of the normal ways to express possession in Norwegian.

A very common pattern is:

• definite noun + possessive

So:

• hånden hennes = her hand
• boka mi = my book
• vennen din = your friend

English usually puts the possessive first, but Norwegian often puts it after the noun.

Yes, you can.

Both are possible:

• hånden hennes
• hennes hånd

But they are not used in exactly the same way.

• hånden hennes is the more neutral, everyday pattern.
• hennes hånd can sound more formal, literary, or emphatic.

So in ordinary speech, Han kysser hånden hennes is the more natural choice.

Because sin/sitt/sine is used when the possessor is the subject of the sentence.

Here, the subject is:

• Han = he

But the owner of the hand is:

• hennes = her

Since the hand belongs to someone else, not to han, you use hennes.

Compare:

• Han kysser hånden hennes = He kisses her hand
• Han kysser hånden sin = He kisses his own hand

That is a very important difference in Norwegian.

Kysser is the present tense of å kysse.

• å kysse = to kiss
• kysser = kisses / is kissing

In Norwegian, the present tense can often cover both the simple present and the present progressive from English, depending on context.

So Han kysser hånden hennes can mean:

• He kisses her hand
• He is kissing her hand

The infinitive is å kysse.

Forms:

• å kysse = to kiss
• kysser = kisses / is kissing
• kysset = kissed / kissed (past / past participle, depending on context)

So kysser is just the present-tense form of the verb.

Because Norwegian often adds definiteness to the end of the noun instead of using a separate word.

So:

• hånd = hand
• hånden = the hand

That -en ending is doing the job that the does in English.

This is very normal in Norwegian.

Good question. In Bokmål, hånd can be treated as a feminine noun, but many speakers also use the common-gender/masculine-style definite ending.

So you may see:

• hånda
• hånden

Both can be correct in Bokmål, depending on style and preference.

In this sentence, hånden hennes is perfectly natural.
You might also hear hånda hennes in speech or see it in writing.

The sentence follows normal Norwegian word order:

• Han = subject
• kysser = verb
• hånden hennes = object

So it is:

• Subject + Verb + Object

That matches standard main-clause word order in Norwegian and is similar to English here:

• He kisses her hand

Yes, grammatically it is completely natural.

The action itself—kissing someone’s hand—may sound formal, old-fashioned, romantic, or theatrical depending on context, but the Norwegian sentence is perfectly normal.

So the grammar is everyday Norwegian, even if the situation might feel a bit special.