Vi vil tage færgen til øen og sejle tilbage om aftenen.

Vil can mean both, depending on context.

In this sentence, it most naturally means will / are going to / intend to. So Vi vil tage færgen til øen... means something like We will / we’re going to take the ferry to the island...

If you wanted a stronger sense of want to, Danish often uses gerne vil:

• Vi vil tage færgen = We will / intend to take the ferry
• Vi vil gerne tage færgen = We would like to take the ferry

They are infinitives, the basic verb form.

After a modal verb like vil, Danish uses the infinitive without at:

• vil tage
• vil sejle

So:

• Vi vil tage færgen
• not Vi vil at tage færgen

This is similar to English:

• We will take
• not We will to take

Because one modal verb can govern more than one infinitive when the verbs are linked by og.

So:

• Vi vil tage færgen til øen og sejle tilbage...

means:

• We will take the ferry to the island and sail back...

Danish does not need to repeat vil here. English works the same way:

• We will take the ferry and sail back
• not necessarily We will take the ferry and will sail back

Yes. Tage is commonly used with means of transport, much like English take.

For example:

• tage bussen = take the bus
• tage toget = take the train
• tage færgen = take the ferry

So this is very natural Danish.

Because Danish usually puts the definite article at the end of the noun.

So:

• en færge = a ferry
• færgen = the ferry

and:

• en ø = an island
• øen = the island

This is one of the biggest differences from English. Instead of putting the before the noun, Danish often adds -en or -et to the noun itself.

The noun is ø = island, and the definite ending is simply added:

• ø
  • -en = øen

That is completely normal in Danish, even though it may look unusual to an English speaker.

Pronunciation-wise, øen is typically said as two syllables, roughly like Ø-en.

Because til shows movement toward a destination, while på shows location.

• til øen = to the island
• på øen = on the island

So in this sentence, they are going to the island, which is why til is correct.

Sejle means to sail or more broadly to go by boat / travel by water.
Tilbage means back.

So sejle tilbage means:

• sail back
• go back by boat
• return by water

It does not necessarily mean that the speakers themselves are operating the boat. It can also be used for traveling on a ferry or other boat.

Om aftenen means in the evening or in the evenings, depending on context.

Here it means that the return trip happens in the evening.

A useful comparison:

• i aften = this evening / tonight
• om aftenen = in the evening, often as a time period or general part of the day

So:

• Vi sejler tilbage i aften = We’re sailing back tonight
• Vi sejler tilbage om aftenen = We’re sailing back in the evening

This sentence has normal main-clause word order:

• Vi = subject
• vil = finite verb
• tage / sejle = infinitives
• then the rest of the sentence

So the pattern is:

Subject + finite verb + infinitive(s) + other information

If you move another element to the front, Danish follows the V2 rule, so the finite verb still stays in second position:

• Om aftenen vil vi sejle tilbage.

That is an important Danish pattern to get used to.

Yes. Og simply means and.

It links the two actions:

• tage færgen til øen
• sejle tilbage

So the sentence describes one plan with two connected parts:

1. go to the island by ferry
2. return by boat in the evening

Yes, and that version is also very natural.

The difference is mainly one of nuance:

• Vi vil tage... = We will / intend to / are going to take...
• Vi tager... = We take / are taking / will take, depending on context

In everyday Danish, the present tense is often used for future plans, just like in English:

• Tomorrow we’re taking the ferry
• Danish: I morgen tager vi færgen

So both versions can work, but vil makes the future intention more explicit.