Ikke dropp avtalen.

Because this is a negative command: ikke means not / don't.

In Norwegian, a common way to make a negative imperative is:

Ikke + imperative verb

So:

• Dropp avtalen. = Drop/skip/cancel the agreement/appointment.
• Ikke dropp avtalen. = Don’t drop/skip/cancel the agreement/appointment.

This is very natural in everyday Norwegian.

Dropp is the imperative form of the verb å droppe.

Examples:

• å droppe = to drop / skip / cancel
• dropper = drop(s) / am dropping
• droppet = dropped
• dropp! = drop! / skip it!

In commands, Norwegian often uses the verb stem as the imperative:

• snakke → snakk!
• vente → vent!
• droppe → dropp!

So Ikke dropp avtalen literally has the command form dropp.

Because avtalen is the definite form of avtale.

• en avtale = an agreement / an appointment
• avtalen = the agreement / the appointment

Norwegian usually puts definiteness at the end of the noun:

• en bil = a car
• bilen = the car

So here, avtalen means a specific agreement/appointment that both speaker and listener know about.

Avtale can mean several related things depending on context:

• agreement
• deal
• arrangement
• appointment

So Ikke dropp avtalen could mean:

• Don’t cancel the appointment
• Don’t back out of the agreement
• Don’t drop the deal

The exact meaning depends on the situation. Even if the general meaning is already clear, it helps to know that avtale is a flexible word in Norwegian.

Yes, droppe is very common in everyday Norwegian, especially in speech and informal writing.

It often means:

• to skip
• to leave out
• to cancel
• to stop doing something
• to drop

Examples:

• Jeg droppet møtet. = I skipped/cancelled the meeting.
• Kan vi droppe det? = Can we skip that?
• Han droppet ut av skolen. = He dropped out of school.

It is fairly informal and conversational, but extremely common.

You might understand it, but Ikke dropp avtalen is much more natural.

For negative commands, Norwegian usually puts ikke first:

• Ikke gjør det. = Don’t do that.
• Ikke glem boka. = Don’t forget the book.
• Ikke dropp avtalen. = Don’t drop the agreement/appointment.

Dropp ikke avtalen sounds unusual or marked in normal everyday speech.

It sounds mostly neutral to informal.

That is mainly because of droppe, which is a very everyday verb. If you wanted something more formal, you might choose a different verb depending on the context, for example:

• Ikke avlys avtalen. = Don’t cancel the appointment/agreement.
• Ikke bryt avtalen. = Don’t break the agreement.

So Ikke dropp avtalen is natural spoken Norwegian, but not especially formal.

A rough guide for an English speaker is:

IK-ke dropp AHV-tah-len

A few tips:

• ikke: the kk is a clear hard sound, and the final e is lightly pronounced.
• dropp: short vowel, then a strong pp sound.
• avtalen: stress is usually on the first syllable: AV-ta-len.

If you want a very rough approximation: IK-ke dropp AV-ta-len

No. It is optional.

You can write:

• Ikke dropp avtalen.
• Ikke dropp avtalen!

With a period, it sounds like a calm instruction or reminder.
With an exclamation mark, it sounds stronger or more urgent.

Both are correct.

Yes, depending on what you mean exactly.

If you mean don’t cancel the appointment, you could say:

• Ikke avlys avtalen.

If you mean don’t break the agreement, you could say:

• Ikke bryt avtalen.

If you mean don’t skip it / don’t back out, then:

• Ikke dropp avtalen.

So this sentence is natural, but the best verb depends on whether the avtale is an appointment, a deal, or a promise-like agreement.