I morgen vil jeg få klippet håret hos frisøren, fordi det er blevet for langt.

Because Danish main clauses follow the V2 rule: the finite verb must come in second position.

So when I morgen is placed first, the verb vil has to come next, and the subject jeg comes after it:

I morgen vil jeg få klippet håret ...

If you started with the subject instead, you would get:

Jeg vil få klippet håret i morgen.

Both are correct; the first one emphasizes tomorrow.

Danish does not have a separate future tense ending like some languages do. Future meaning is usually expressed with:

• the present tense, or
• a modal verb such as vil or skal

Here, vil means something like will or intend to.

So I morgen vil jeg få klippet håret means Tomorrow I will get my hair cut.

In some contexts, Danish could also simply use the present tense:

I morgen får jeg klippet håret.

That can also mean Tomorrow I’m getting my hair cut.

Because få + past participle is a very common Danish structure meaning to get something done.

So:

• få klippet håret = get one’s hair cut
• få repareret bilen = get the car repaired
• få taget et billede = get a picture taken

If you said jeg vil klippe håret, that would more directly mean I will cut the hair, which sounds like you are doing the cutting yourself.

But at a salon, the normal idea is that someone else does it for you, so få klippet håret is the natural choice.

Klippet is the past participle of klippe.

In the pattern få + past participle, the participle describes the result of the action:

• få klippet håret = get the hair cut
• få skrevet brevet = get the letter written

So klippet does not mean past time here by itself. It is just the form Danish uses in this construction.

In Danish, body parts are often expressed with the definite form when it is already obvious whose body part is meant.

So Danish often says:

• vaske hænderne = wash one’s hands
• brækkede benet = broke one’s leg
• få klippet håret = get one’s hair cut

Using mit hår is possible, but it usually adds emphasis or contrast:

Jeg vil have klippet mit hår, ikke dit.

In your sentence, håret is the natural default.

Hos is used when talking about being at someone’s place, especially with professionals or service providers.

So:

• hos frisøren = at the hairdresser’s / with the hairdresser
• hos lægen = at the doctor’s
• hos tandlægen = at the dentist’s

It fits well here because the idea is that the haircut happens there, by that professional.

Yes, in many situations til frisøren is also possible, but the nuance is slightly different.

• til frisøren often emphasizes going to the hairdresser
• hos frisøren emphasizes being at the hairdresser’s / with the hairdresser

So:

• Jeg skal til frisøren i morgen = I’m going to the hairdresser tomorrow
• Jeg får klippet håret hos frisøren = I get my hair cut at the hairdresser’s

In your sentence, hos frisøren is very natural because it focuses on where the haircut is being done.

After hos, Danish very often uses the definite form with professions when talking about the relevant professional in the situation.

For example:

• hos lægen
• hos tandlægen
• hos frisøren

This is similar to English expressions like at the doctor’s or at the hairdresser’s.

It does not have to mean one very specific hairdresser already mentioned earlier; it is just the normal idiomatic way to say it.

Fordi means because and introduces a subordinate clause:

fordi det er blevet for langt

A useful thing to notice is that Danish subordinate clauses do not use the main-clause V2 pattern. So the order stays more like:

subject + verb

Here:

• det = subject
• er blevet = verb phrase

That is why you get:

fordi det er blevet for langt

not a V2-type order.

Er blevet is the present perfect of blive, and here it means has become or has gotten.

So:

det er blevet for langt = it has become too long / it has gotten too long

With blive, Danish uses er in this perfect form:

• det er blevet koldt = it has gotten cold
• han er blevet træt = he has become tired

So er blevet is the correct form here.

Here for means too.

So:

• for langt = too long
• for dyrt = too expensive
• for sent = too late

This is a very common use of for before adjectives and adverbs.

Because the adjective agrees with det, which refers back to håret.

Hår is grammatically neuter, so the adjective takes the -t form:

• lang = common gender form
• langt = neuter form

So:

• en lang dag = a long day
• et langt hår = long hair
• det er blevet for langt = it has become too long

That -t is there because the thing being described is neuter.

Yes. Your sentence is completely correct and natural, but Danish also often uses shorter everyday versions such as:

I morgen skal jeg have klippet håret, fordi det er blevet for langt.

or even:

Jeg skal til frisøren i morgen, fordi mit hår er blevet for langt.

These are slightly different in structure, but the meaning is basically the same. Your original sentence is good Danish.