Padlegruppen øver på sveipetaket sammen.

Because Norwegian often makes compound nouns by joining words together.

• padle = paddle
• gruppen = the group

So padlegruppen literally means the paddling group or the paddle group.

This is very common in Norwegian. Where English often uses two words, Norwegian often prefers one:

• fotballag = football team
• skolebuss = school bus
• padlegruppe = paddling group

In the sentence, padlegruppen is the definite form: the paddling group.

The ending -en marks the noun as definite singular for many masculine nouns.

Here is the pattern:

• en padlegruppe = a paddling group
• padlegruppen = the paddling group

So instead of using a separate word for the, Norwegian often adds the definiteness to the end of the noun.

This is one of the most important features of Norwegian nouns.

Because the verb å øve often takes the preposition på when talking about what someone is practicing.

So:

• å øve på noe = to practice something
• å øve på sveipetaket = to practice the sweep stroke

This is just the normal pattern with this verb in many contexts.

Examples:

• Jeg øver på norsk. = I’m practicing Norwegian.
• Hun øver på sangen. = She’s practicing the song.
• Vi øver på teknikken. = We’re practicing the technique.

So på is not optional here in natural Norwegian.

It is another compound noun:

• sveip = sweep
• tak = stroke / pull / movement
• sveipetak = sweep stroke
• sveipetaket = the sweep stroke

The ending -et here marks the noun as definite singular, because tak is a neuter noun.

Compare:

• et sveipetak = a sweep stroke
• sveipetaket = the sweep stroke

So both padlegruppen and sveipetaket are definite nouns, but they take different endings because they belong to different grammatical genders.

Norwegian uses the definite form when referring to something specific or already known from context.

In this sentence:

• padlegruppen = a specific paddling group
• sveipetaket = a specific stroke/technique

This often sounds natural when talking about:

• known groups
• named techniques
• something already understood in the situation

If you changed them to indefinite, the meaning would become more general:

• En padlegruppe øver på et sveipetak.

That sounds less natural in many contexts unless you are introducing them for the first time in a very general way.

It is singular.

Even though a group contains several people, the noun gruppe is grammatically one thing, so the verb agrees as singular:

• Padlegruppen øver ...

This is similar to English the group practices ...

If you wanted a plural subject, you would need a plural noun, for example:

• Padlerne øver på sveipetaket sammen. = The paddlers practice the sweep stroke together.

So the sentence focuses on the group as one unit.

Sammen means together.

It tells you how they are practicing: they are doing it together, not individually.

In this sentence it comes at the end, which is very natural:

• Padlegruppen øver på sveipetaket sammen.

You can often place sammen in slightly different positions, but the final position is common and clear.

Examples:

• Vi jobber sammen. = We work together.
• De trener sammen. = They train together.

Because Norwegian is generally a V2 language in main clauses. That means the finite verb usually comes in the second position.

Here the structure is:

• Padlegruppen = subject
• øver = finite verb
• på sveipetaket = prepositional phrase
• sammen = adverb

So:

• Padlegruppen øver på sveipetaket sammen.

If you move another element to the front, the verb still stays second:

• Sammen øver padlegruppen på sveipetaket.
• På trening øver padlegruppen på sveipetaket.

That verb-second pattern is a key feature of Norwegian sentence structure.

Normally, no. That sounds unnatural.

With å øve, Norwegian usually uses på before the thing being practiced:

• øve på en teknikk
• øve på en sang
• øve på uttale
• øve på sveipetaket

So the natural sentence is:

• Padlegruppen øver på sveipetaket sammen.

Leaving out på would sound wrong to most speakers.

The letter ø is a front rounded vowel that does not exist in standard English.

A rough guide:

• ø is somewhat like the vowel in French bleu or German schön
• Your tongue is placed somewhat like for e, but your lips are rounded

So øver is roughly:

• Ø-ver

Also note:

• ø and o are different sounds
• øver and a hypothetical form with o would not sound the same

It usually takes some practice, and that is completely normal for English speakers.

Yes. Øver is the present tense form of å øve.

The basic forms are:

• å øve = to practice
• øver = practice / is practicing
• øvde = practiced / was practicing
• har øvd = have practiced

So the sentence describes something happening now, regularly, or in a general present-time situation:

• Padlegruppen øver på sveipetaket sammen.