Vi kan gå derhen til fods.

Here is a word-by-word breakdown:

• Vi = we
• kan = can
• gå = walk / go
• derhen = there / to that place
• til fods = on foot

So the sentence is built very straightforwardly:

• subject: Vi
• finite verb: kan
• infinitive: gå
• direction: derhen
• manner/means: til fods

Kan can mean a few related things in Danish, just like can in English:

• ability: we are able to
• possibility: it’s possible for us to
• sometimes permission: we may

In this sentence, the most natural reading is usually ability or practical possibility. For example, if you are discussing transport, it often means something like we can get there by walking.

Because kan is a modal verb.

In Danish, modal verbs such as:

• kan = can
• vil = will / want to
• skal = must / will
• må = may / must
• burde = ought to

are followed by an infinitive.

So:

• kan is the conjugated verb
• gå stays in the infinitive

That is exactly parallel to English can go.

Because after a modal verb, Danish uses the bare infinitive.

So you say:

• Vi kan gå
• Han vil komme
• De skal arbejde

not:

• Vi kan at gå

This is very similar to English:

• we can go
• not we can to go

This is an important distinction.

• der usually means there as a location
• derhen usually means to there / over there with a sense of movement toward a place

Compare:

• Vi er der. = We are there.
• Vi går derhen. = We are walking there.

So in your sentence, derhen fits because the sentence describes movement.

Til fods is a fixed expression meaning on foot.

The form fods may look strange, because modern Danish normally uses fod for foot and fødder for feet. In til fods, the -s is part of an old fixed form that has survived in the expression.

So the best way to learn it is simply as a set phrase:

• til fods = on foot

You do not usually build new phrases with fods in the same way.

Yes, a little — but it is still understandable and natural enough.

Since gå already means walk, the phrase til fods adds extra emphasis to the idea of going on foot rather than by some other means.

Compare:

• Vi kan gå derhen. = We can walk there.
• Vi kan gå derhen til fods. = We can go there on foot, with extra emphasis on the method

In many contexts, Vi kan gå derhen would be enough.

Yes.

• Vi kan gå derhen. = We can walk there.
• Vi kan gå til fods. = We can go on foot / we can walk.

If you remove derhen, you lose the explicit destination. If you remove til fods, the sentence is still clear because gå already suggests walking.

So both shorter versions are perfectly possible, depending on what you want to emphasize.

In this meaning, you should normally write it as one word: derhen.

For a learner, the safe choice is:

• Vi kan gå derhen.

There are cases in Danish where elements like this can be separated in other structures or with special emphasis, but as a standard adverb meaning to that place, derhen is the form to learn.

People would understand it, but Vi kan gå derhen til fods is more natural.

Why?

Because derhen belongs closely with the idea of movement:

• gå derhen = walk there

Then til fods adds the manner:

• gå derhen til fods

So the usual order is:

1. verb phrase
2. destination/direction
3. manner

In a yes/no question, Danish normally puts the finite verb first.

So:

• statement: Vi kan gå derhen til fods.
• question: Kan vi gå derhen til fods?

This is similar to English:

• We can walk there.
• Can we walk there?

So the only change is the inversion of vi and kan.