Har du någonsin gjort ett misstag?

Because Swedish forms most yes/no questions by putting the finite verb first.

• Statement: Du har någonsin gjort ett misstag would not be a normal sentence, but the key idea is that du har is the statement order.
• Question: Har du ... ? = verb first, then subject.

So Har du ... ? works like English Have you ... ?

Har gjort is the Swedish present perfect, just like have done in English.

• har = have
• gjort = past participle of göra = done

So:

• Har du gjort ett misstag? = Have you made/done a mistake?
• Gör du ett misstag? would mean Are you making a mistake? or Do you make a mistake?, which is a different idea.

Since the sentence includes någonsin meaning ever, the present perfect is the natural choice.

Gjort is the past participle of the verb göra, which means to do or sometimes to make.

Common forms are:

• infinitive: göra
• present: gör
• past: gjorde
• supine / participle used with har: gjort

In this sentence, Swedish uses gjort with har to make the present perfect: har gjort.

Någonsin means ever.

It is used in questions and some other contexts to talk about at any time in your life or at any time at all.

So:

• Har du någonsin gjort ett misstag? = Have you ever made a mistake?

It adds the idea of at any point, even once.

In Swedish, adverbs like någonsin often come between the auxiliary verb and the main verb.

So the pattern is:

• Har du någonsin gjort ... ?

This is very similar to English:

• Have you ever made ... ?

Compare:

• har = auxiliary
• någonsin = adverb
• gjort = main verb form

That position is the most natural one here.

Because misstag is a Swedish neuter noun, and neuter nouns take ett in the indefinite singular.

So:

• ett misstag = a mistake

In Swedish, nouns are divided into two grammatical genders:

• en-words
• ett-words

Misstag happens to be an ett-word, so you must say ett misstag.

Yes, misstag means mistake, and it is used very much like English mistake.

For example:

• göra ett misstag = make a mistake

Notice that Swedish uses göra (do/make) here, just as English says make a mistake rather than do a mistake.

So although göra often means do, in some expressions it corresponds to English make.

Yes, that is possible, and it means something very similar.

• någonsin = ever
• någon gång = sometime / ever / at some point

So both can work in questions like this. However:

• Har du någonsin gjort ett misstag? sounds a bit more direct and standard for Have you ever made a mistake?
• Har du gjort ett misstag någon gång? is also natural, but slightly more like Have you made a mistake at some point?

It is grammatically correct and natural, but in real life it may sound a bit rhetorical, humorous, or dramatic, because the expected answer is obviously yes.

A Swedish speaker might use it:

• jokingly
• rhetorically
• to introduce a discussion
• for emphasis

So the sentence is good Swedish, even if the content is a little playful.

A few simple answers are:

• Ja. = Yes.
• Ja, det har jag. = Yes, I have.
• Nej. = No.
• Nej, det har jag inte. = No, I haven’t.

The very common short-answer pattern is:

• Det har jag. = I have.
• Det har jag inte. = I haven’t.

Du means you.

It is usually pronounced roughly like:

• doo

In normal speech, it may sound a bit shorter or lighter depending on the speaker, but for a learner doo is a good approximation.

So the sentence begins:

• Har du ... ? ≈ har doo ... ?

The structure is:

• Har = auxiliary verb
• du = subject
• någonsin = adverb
• gjort = main verb form
• ett misstag = object

So:

• Har
  • du
    • någonsin
      • gjort
        • ett misstag?

This is a very useful model for many Swedish questions in the present perfect, such as:

• Har du någonsin varit i Sverige? = Have you ever been to Sweden?
• Har du någonsin sett den filmen? = Have you ever seen that movie?