Har du nogensinde set det?

Because this is a yes/no question in Danish. In main-clause questions like this, the verb comes first:

• Har du ...? = Have you ...?

This is similar to English inversion:

• You have seen it. → statement
• Have you seen it? → question

So Har du nogensinde set det? follows the normal Danish pattern for a yes/no question.

Nogensinde means ever.

So:

• Har du set det? = Have you seen it?
• Har du nogensinde set det? = Have you ever seen it?

It adds the idea of at any time in your life / at any point before now.

In Danish, adverbs like nogensinde often appear after the subject and before the main verb or participle.

Here the structure is:

• Har = auxiliary verb
• du = subject
• nogensinde = adverb
• set = past participle
• det = object

So the word order is very natural Danish:

• Har du nogensinde set det?

This is similar to English Have you ever seen it?, where ever also comes before seen.

Set is the past participle of the verb at se (to see).

The basic forms are:

• at se = to see
• ser = see / sees
• så = saw
• set = seen

So:

• Jeg ser det. = I see it.
• Jeg så det. = I saw it.
• Jeg har set det. = I have seen it.

Har set is the present perfect, like English have seen.

It is used when talking about something that happened at some time before now, especially when the exact time is not important.

So:

• Har du nogensinde set det? = Have you ever seen it?

If you used the simple past, it would suggest a more specific past event, more like Did you see it? rather than Have you ever seen it?

Det means it.

It is the pronoun used for a neuter noun or for something previously mentioned more generally. In this sentence, it refers to the thing being talked about.

So:

• set det = seen it

Danish often uses det where English uses it.

Danish has two common words for it:

• den for common gender nouns
• det for neuter nouns

Examples:

• en film → Har du set den? = Have you seen it?
• et hus → Har du set det? = Have you seen it?

But Danish also uses det in some more general situations, especially when referring to an idea, situation, or something not tied closely to a specific noun.

A careful pronunciation is roughly:

• Har = like ha with a soft Danish r
• du = doo
• nogensinde = roughly NO-gen-sin-de
• set = close to seth/sed depending on accent
• det = often pronounced more like deh in connected speech

In natural speech, Danish often reduces sounds, so the whole sentence may sound smoother and less clearly separated than the spelling suggests.

A rough English-style guide could be:

ha doo NO-gen-sin-de set deh?

But this is only approximate, since Danish vowels and soft consonants do not match English exactly.

Yes. If you leave it out, the sentence still works:

• Har du set det? = Have you seen it?

Adding nogensinde makes it specifically mean:

• Have you ever seen it?

So the version without nogensinde is more neutral, while the version with it emphasizes at any time before now.

Yes, it is completely natural.

Har du nogensinde set det? is a normal and idiomatic way to ask Have you ever seen it?

In casual speech, people might also say:

• Har du set det før? = Have you seen it before?

That can sometimes overlap in meaning, but nogensinde is the clearest match for ever.

As a statement, the verb would no longer come first. For example:

• Du har nogensinde set det. is not natural Danish.

A natural statement would usually be something like:

• Du har set det. = You have seen it.
• Du har aldrig set det. = You have never seen it.
• Har du nogensinde set det? = Have you ever seen it?

So while the question with nogensinde is very natural, a plain statement with nogensinde is much less common unless the sentence is structured differently.