Du behøver ikke at tale så højt; der er allerede nok støj i rummet.

You do not need to speak so loudly; there is already enough noise in the room.

Breakdown of Du behøver ikke at tale så højt; der er allerede nok støj i rummet.

• i: in
• være: to be
• rummet: the room
• at: to

Questions & Answers about Du behøver ikke at tale så højt; der er allerede nok støj i rummet.

Why does the sentence use behøver ikke at instead of just ikke with another verb?

Behøver means need or have to, so Du behøver ikke at tale så højt means You don’t need to speak so loudly.

This is different from simply negating tale:

• Du taler ikke så højt = You are not speaking that loudly
• Du behøver ikke at tale så højt = You don’t need to speak that loudly

So behøver ikke expresses lack of necessity, not just simple negation.

Also, Danish often uses behøve in negative sentences:

• Du behøver ikke komme = You don’t need to come
• Jeg behøver ikke vente = I don’t need to wait

Why is there an at in ikke at tale? Can it be left out?

Yes, at can often be left out after behøver in everyday Danish.

So both are possible:

• Du behøver ikke at tale så højt
• Du behøver ikke tale så højt

Both are natural. The version with at can sound a little more careful or formal in writing, but neither is strange.

This is similar to English having both:

• You don’t need to speak
• You don’t need to be speaking
  Not exactly the same structure, but the idea is that small function words may be included or omitted depending on style.