Kan De se, om dette kaffefilter passer til den nye kaffemaskine?

De is the formal/polite way to say you in Danish.

It is capitalized to distinguish it from de, which normally means they. In modern Danish, De is much less common than it used to be. Most people would usually say du instead.

So this sentence sounds polite, formal, or a bit old-fashioned.

Because this is a yes/no question, and in Danish the finite verb often comes first in that kind of question.

• Statement: De kan se, om dette kaffefilter passer ...
• Question: Kan De se, om dette kaffefilter passer ...?

So Kan at the beginning is just normal Danish question word order.

Not exactly in the physical-eyesight sense.

In Danish, se, om ... often means something like:

• see whether
• check whether
• find out whether
• tell whether

So Kan De se, om ... is a very natural way to ask someone to check or determine something.

Here om means whether or if in an indirect question.

So:

• Kan De se, om dette kaffefilter passer ...? = Can you see/check whether this coffee filter fits ...?

This is different from hvis, which means if in a conditional sense:

• Hvis det passer, køber jeg det = If it fits, I’ll buy it

So in this sentence, om is the correct word.

Because kaffefilter is a neuter noun.

In Danish, the singular demonstratives are:

• denne for common gender
• dette for neuter

The noun is et kaffefilter, so it takes dette:

• dette kaffefilter

A useful rule is that in compound nouns, the last part determines the gender. Here the last part is filter, and et filter is neuter.

Because Danish writes compound nouns as one word.

So:

• kaffe
  • filter → kaffefilter
• kaffe
  • maskine → kaffemaskine

This is very common in Danish. English often writes similar expressions as two words, but Danish usually joins them.

The last part is the main noun:

• kaffefilter = a kind of filter
• kaffemaskine = a kind of machine

Passe til is a fixed expression meaning:

• fit
• go with
• be suitable for
• be compatible with

In this sentence, it means that the filter is the right type for the machine.

So passer til den nye kaffemaskine means something like fits the new coffee machine or is suitable for the new coffee machine.

The preposition til is part of the expression here, so it is important to learn passe til together.

Because nye is the form used in a definite phrase with an adjective.

Compare:

• en ny kaffemaskine = a new coffee machine
• den nye kaffemaskine = the new coffee machine

So after den/det/de, the adjective usually takes the -e form:

• den nye
• det nye
• de nye

That is why ny becomes nye here.

Because Danish normally does not add the definite ending to the noun when there is a determiner like den plus an adjective before it.

So Danish says:

• kaffemaskinen = the coffee machine
• den nye kaffemaskine = the new coffee machine

This is an important pattern in Danish:

• the house = huset
• the big house = det store hus

So in this sentence, den nye kaffemaskine is exactly what you should expect.

Because after om, you have a subordinate clause, and subordinate clauses normally keep the order subject + verb.

So:

• Main question: Kan De se ...?
• Subordinate clause: om dette kaffefilter passer til den nye kaffemaskine

In other words:

• dette kaffefilter = subject
• passer = verb

This is different from main yes/no questions, where the verb often comes first.

Yes, it is grammatical and understandable, but De makes it sound quite formal.

In everyday modern Danish, many speakers would more naturally say:

• Kan du se, om dette kaffefilter passer til den nye kaffemaskine?

And in very natural spoken Danish, you might also hear something like:

• Kan du se, om det her kaffefilter passer til den nye kaffemaskine?

So the sentence is correct, but its level of politeness/register is something learners should notice.