Der vs Som: Choosing the Relative

Danish has two relative pronouns, der and som, that both translate to English "who/which/that" — but they are not interchangeable. The single rule that governs the choice is about the grammatical role of the gap in the relative clause: when the relativised element is the subject, you may use either der or som; when it is the object, you must use som (or leave it out entirely), and der is simply impossible.

The quick answer

Is the gap the SUBJECT of the relative clause? Yes → der or som (both fine) No (it's the object, or governed by a preposition) → som or nothing (Ø); der is impossible

So som is the safe all-rounder — it works in every position. Der is the specialist that only works in subject position. If you ever feel unsure, som will never be wrong on these grounds.

Finding the gap: the core skill

A relative clause modifies a noun, and inside it there is a "gap" — the spot where that noun would have stood if the clause were a full sentence. To choose correctly, identify whether that gap is the subject (the doer) or the object (the done-to).

Take manden der bor her ("the man who lives here"). Unfold the relative clause: [manden] bor her — "the man lives here." The man does the living; he is the subject. Subject gap → der or som both work.

Now take bogen jeg læser ("the book I'm reading"). Unfold it: jeg læser [bogen] — "I read the book." Here jeg is the subject and bogen is the object. Object gap → som or nothing, never der.

Case 1: Subject relative — der or som

When the relativised noun is the subject of the relative clause, both pronouns are available and mean the same thing. Der is slightly more common in everyday speech; som is equally correct and a touch more explicit.

In every one of these, the relative word is the subject of its clause (the man lives, the girl speaks, the train goes), so der and som are interchangeable.

One thing you may not do with a subject gap is drop the pronoun: Danish requires der or som to be present when it's the subject. The relative word can only vanish when it's the object (next section).

Case 2: Object relative — som or nothing (never der)

When the relativised noun is the object of the verb inside the clause, der is ungrammatical. Your options are som — or simply nothing at all, which is extremely common and natural.

In all of these the gap is the object — jeg læser [bogen], vi så [filmen] — so som is optional and der is off the table. English works the same way here ("the book I'm reading" with no "that"), so the omission feels natural to English speakers; the trap is only the der.

Case 3: Prepositional relative

When the relativised noun is governed by a preposition, Danish most often leaves the preposition stranded at the end of the clause (just like informal English "the house I live in"). The relative word is again an object — of the preposition — so the rule is the same as Case 2: som or nothing, never der.

The stranded i and med sit at the clause's end; the relative slot they fill is an object slot, so der is impossible. (A formal, literary alternative fronts the preposition: Huset, i hvilket jeg bor — but this is stiff and rare in speech; everyday Danish strands the preposition.)

Why der can't be an object

It helps to know why the asymmetry exists. The relative der is historically the same word as the existential/expletive der in der er ("there is"), which always occupies the subject position of its clause. That subject-bound history is why relative der can only ever fill a subject gap. Som, by contrast, started life as a more general linking word and never got locked to the subject slot — so it ranges freely across subject, object, and prepositional positions. You don't have to memorise the history, but it explains the lopsided rule: one word is a subject specialist, the other is a generalist.

Edge case: der vs the adverb der

Don't confuse the relative pronoun der with the adverb der meaning "there." Der står en mand der ("a man is standing there") contains both: the first der is the existential subject-filler, the last der is the place adverb "there." Neither is the relative pronoun. Context and position keep them apart, but the spelling overlap is worth flagging.

Common Mistakes

By far the dominant error is using der for an object gap, because English "that/who" doesn't distinguish subject from object and learners reach for the more frequent der.

Two rules cure almost everything: (1) der is only for subjects; (2) a subject relative may not be dropped, but an object relative may.

Decision table

Key takeaways

• One question: is the gap the subject of the relative clause? Yes → der or som. No → som or nothing.
• Der can never be an object — not of a verb, not of a preposition.
• A subject relative cannot be omitted; an object relative can (and often is).
• When in doubt, som is always grammatically safe — it works in every slot.