Helikopteret flyr over byen.

In Norwegian, the definite article is usually attached to the end of the noun.

• et helikopter = a helicopter
• helikopteret = the helicopter

The ending -et is the definite singular ending for many neuter nouns. So helikopter is a neuter noun.

For the same reason: Norwegian often adds the definite article to the noun itself.

• en by = a town / a city
• byen = the town / the city

Here, by is a common gender noun, so its definite singular form takes -en.

Flyr is the present tense of å fly.

• å fly = to fly
• flyr = flies / is flying

Norwegian verbs do not change for person the way English verbs do. So the same form works with all subjects:

• jeg flyr = I fly / I am flying
• du flyr = you fly / are flying
• helikopteret flyr = the helicopter flies / is flying

Norwegian often uses the simple present where English might use either flies or is flying.

So Helikopteret flyr over byen can match English:

• The helicopter flies over the city
• The helicopter is flying over the city

Which one sounds best in English depends on context, but the Norwegian sentence itself is completely normal.

Over usually means over, above, or sometimes across, depending on context.

In this sentence, it most naturally means that the helicopter is moving above the city. So over byen means over the city.

This is the normal word order for a basic statement in Norwegian:

subject + verb + rest of the sentence

So here:

• Helikopteret = subject
• flyr = verb
• over byen = prepositional phrase

This is similar to normal English word order.

Yes. In a yes/no question, Norwegian usually puts the verb before the subject:

• Flyr helikopteret over byen? = Is the helicopter flying over the city?

That verb-second pattern is very important in Norwegian.

It can mean either town or city, depending on context.

So byen may be translated as:

• the town
• the city

If the meaning has already been given to you as city, that is a perfectly natural translation here.

A rough English-friendly guide would be:

heh-li-kop-ter-eh flyr OH-ver BEE-en

A few helpful notes:

• y in flyr is not like normal English y. It is a rounded vowel that English does not really have.
• byen is usually pronounced as two syllables, roughly BEE-en.
• The r sound may vary depending on dialect.

You do not need perfect pronunciation right away; getting the endings and rhythm right is already a good start.

Yes, but it means something slightly different.

• Helikopteret flyr over byen = the helicopter is flying over the city
• Helikopteret er over byen = the helicopter is over the city

The first sentence focuses on the action of flying. The second focuses more on location.