Vennligst ring på når du kommer.

Vennligst means please, but it is often a bit more formal or written-sounding than the English please.

In Norwegian, you will often hear:

• Vær så snill = please, more conversational
• Vennligst = please, often used in notices, instructions, or polite requests

So Vennligst ring på når du kommer sounds polite and fairly neutral, but a little more formal than everyday speech.

Because å ringe på is a fixed expression meaning to ring the doorbell / buzz.

Compare:

• å ringe = to call someone on the phone, or to ring in general
• å ringe på = to ring at the door / press the bell

So in this sentence, på is not optional. It is part of the verb expression.

Here på does not literally mean on in a way that helps much word-for-word. It is part of the phrasal verb ringe på.

This is similar to how English has expressions like:

• come in
• sit down
• turn on

The little word is part of the full meaning. So it is best to learn å ringe på as one unit.

In Norwegian, when talking about the future after words like når (when), Norwegian usually uses the present tense, not a special future form.

So:

• når du kommer = when you come / when you arrive

This is very natural in Norwegian. English also often does something similar:

• Call me when you arrive not
• Call me when you will arrive

So kommer is exactly what you would expect here.

Because Norwegian often uses the present tense to talk about future events, especially in time clauses.

Here, når du kommer refers to a future event, but Norwegian still uses present tense:

• når du kommer
• før du går
• etter at han drar

This is completely normal. The future meaning comes from the context, not from a future verb form.

Because når du kommer is a subordinate clause.

In a normal main clause, Norwegian often has the verb in second position:

• Du kommer
• Kommer du?

But after a subordinating word like når, the word order is usually:

• når + subject + verb

So:

• når du kommer = correct
• når kommer du would normally be a question: when are you coming?

That is an important difference.

It is polite and natural, but slightly on the formal side because of vennligst.

You might see or hear it:

• in messages to visitors
• on signs
• in apartment buildings
• in polite written communication

In more casual speech, people might simply say:

• Ring på når du kommer.
• Bare ring på når du kommer.

So the sentence is perfectly natural, just a bit more polished because of vennligst.

Yes, but the tone changes slightly.

For example:

• Vær så snill å ringe på når du kommer.
• Ring på når du kommer, vær så snill.

These sound polite too, but vær så snill is usually more conversational and personal.

Very roughly:

• vennligst = polite, slightly formal, often written
• vær så snill = polite, more everyday, often spoken

Literally, kommer is from å komme, meaning to come. But in this sentence, the most natural English meaning is often arrive.

So når du kommer is literally when you come, but in context it means:

• when you arrive
• when you get here

This is very common in Norwegian.

Yes. Å ringe på can be used for ringing at someone’s door in general, including:

• a doorbell
• an apartment buzzer
• an entry bell/intercom

So the sentence does not force one specific device. It just means to signal at the door when you get there.

Putting vennligst at the beginning is very common in polite requests and instructions. It clearly sets the polite tone right away.

Compare:

• Vennligst ring på når du kommer. = very natural
• Ring på når du kommer, vennligst. = possible, but often sounds stiffer or less natural
• Ring vennligst på når du kommer. = not natural

So sentence-initial vennligst is usually the best choice here.

Yes. Ring is the imperative form of å ringe.

The imperative is used for commands, requests, and instructions:

• Ring! = Call! / Ring!
• Kom! = Come!
• Vent! = Wait!

So the structure is:

• Vennligst = please
• ring på = ring the bell / buzz
• når du kommer = when you arrive

In other words, this is a polite imperative sentence.