The ordinary restrictive relative — maðurinn sem ég sá "the man (that) I saw" — has its home in the Syntax group, and this page assumes it. Here we go up a level to the relative constructions that an educated native uses without thinking but that no beginner's course names: free (headless) relatives ("whoever wants may come", "what you say is true"), non-restrictive relatives that comment on the head rather than restrict it, relatives that need a resumptive pronoun because the gap sits in an oblique or possessive slot sem cannot reach, and infinitival relatives. The single organising fact, and the one an English speaker must internalise, is that Icelandic has no dedicated "whoever / what" pronoun at all. It builds a free relative out of two pieces: a demonstrative that declines (sá / sú / það / þeir …, and the -gi word hver) plus the invariant complementiser sem. (For the bare sem relative see relative-sem and relative-clauses; for the demonstrative paradigm, sá / sú / það as pronouns.)
Free relatives: a demonstrative + sem, never a bare wh-word
A free or headless relative is a relative clause that is itself an argument — there is no separate noun for it to modify. English packs this into a single wh-word: whoever, whatever, what ("What you said hurt me"; "Whoever did this will pay"). Icelandic has no such single word. It assembles the meaning from a demonstrative head + sem:
- sá sem = "the one who / he who / whoever" (masc.)
- sú sem = "the one who / whoever" (fem.)
- það sem = "what / that which" (neuter — for things and propositions)
- þeir / þær / þau sem = "those who / the ones who" (plural)
- hver sem = "whoever" (free-choice, "no matter who")
The demonstrative carries the gender, number, and case that the outer clause assigns to the whole free relative; sem never changes. So the work of the English -ever word is split across a declining word and a frozen one.
Sá sem hlær síðast hlær best.
He who laughs last laughs best. — free relative as subject; 'sá' is nominative because the whole clause is the subject of 'hlær'.
Það sem þú segir er rétt.
What you say is true. — neuter 'það sem' = 'what / that which'; the free relative is the subject of 'er'.
Ég skil ekki það sem þú átt við.
I don't understand what you mean. — 'það sem' is the OBJECT of 'skil', so the neuter takes the form 'það' (acc = nom here), 'sem' opens the relative.
The neuter það sem is the one English speakers reach for least naturally, because English just says what. Train the substitution "what" → það sem: what you said = það sem þú sagðir, what matters = það sem skiptir máli, everything (that) = allt það sem / allt sem.
hver sem — free-choice "whoever / no matter who"
Alongside sá sem there is hver sem "whoever (it may be)", the free-choice variant that stresses indifference to identity — "no matter who". Here hver itself declines (it is the interrogative/indefinite "who, which"), and sem follows it. The difference from sá sem is subtle: sá sem picks out a specific eventual referent ("the (one) person who…"), while hver sem sweeps over all candidates ("anyone at all who…"). Because hver sem describes an open, non-specific type, its verb is often subjunctive (see subjunctive vs indicative in relatives).
Hver sem vill má koma.
Whoever wants to may come. — free-choice 'hver sem' + the modal; 'hver' is nominative (subject of 'vill'). The crucial point: NOT bare 'hver vill'.
Hvað sem þú gerir, ekki segja henni frá þessu.
Whatever you do, don't tell her about this. — neuter 'hvað sem' = 'whatever'; concessive free relative.
Hverjum sem er, þá er þetta ekki í lagi.
To whomever it may concern, this is not acceptable. — 'hverjum' is DATIVE (the role demanded inside), showing 'hver' declines while 'sem' does not.
Note the parallel with English who vs whoever: English adds -ever; Icelandic adds sem. And just as English whoever is two morphemes glued together (who + ever), Icelandic keeps the two words separate and lets the first one inflect.
Non-restrictive relatives: a parenthetical comment
A restrictive relative narrows down which referent is meant (maðurinn sem ég sá — which man? the one I saw). A non-restrictive (appositive) relative does the opposite: the head is already identified, and the relative simply adds a parenthetical comment about it. In writing it is set off by commas; in speech, by a separate intonation contour and a slight pause.
Pabbi minn, sem er sjötugur í dag, ætlar að halda upp á það með allri fjölskyldunni.
My dad, who turns seventy today, is going to celebrate it with the whole family. — non-restrictive: 'pabbi minn' is already identified; the relative just adds information, set off by commas.
Reykjavík, sem er nyrsta höfuðborg í heimi, dregur að sér ferðamenn allt árið.
Reykjavík, which is the world's northernmost capital, draws tourists all year round. — appositive comment on a uniquely identified head.
Hún gaf mér bókina sína, sem ég hafði lengi langað til að lesa.
She gave me her book, which I had long wanted to read. — non-restrictive 'sem'-clause commenting on the already-specified 'bókina sína'.
Two things English speakers should note. First, Icelandic uses sem in both restrictive and non-restrictive relatives — there is no that/which split as in careful English (the book that I read vs the book, which …). The only signal of non-restrictiveness is the comma and intonation, not the choice of relativiser. Second, a non-restrictive relative can take a whole clause as its antecedent, with neuter sem (or það sem) picking up "the fact just stated":
Hann mætti klukkutíma of seint, sem fór mjög í taugarnar á mér.
He showed up an hour late, which really got on my nerves. — the 'sem'-clause comments on the WHOLE preceding event, not on any single noun.
Resumptive pronouns: filling a gap sem cannot reach
Here is the genuinely advanced point, and the one most worth your attention. The plain relativiser sem corresponds to a gap in the relative clause: maðurinn sem _ kom (subject gap), maðurinn sem ég sá _ (object gap). But some positions cannot host a gap — most importantly the possessor slot and certain prepositional slots. In those cases Icelandic does not drop the position; instead it leaves an ordinary pronoun in place — a resumptive pronoun — that "fills in" for the relativised element.
The textbook case is the possessive relative — English "the man whose name I forgot". Icelandic has no relative whose; it says, literally, "the man that I forgot his name":
Þetta er maðurinn sem ég gleymdi nafninu hans.
This is the man whose name I forgot. — literally 'the man that I forgot the-name his': the possessive 'hans' is a RESUMPTIVE pronoun, because 'sem' cannot relativise a possessor directly.
Ég þekki konuna sem þú varst að tala um börnin hennar.
I know the woman whose children you were just talking about. — resumptive possessive 'hennar' ('her') inside the relative; English 'whose children' has no direct Icelandic counterpart.
The same strategy rescues relatives where the gap would sit inside a preposition phrase deep in the clause, or where leaving a bare gap would be hard to process. Here a resumptive personal/demonstrative pronoun appears in the oblique slot:
Þarna er húsið sem ég sagði þér frá því.
There's the house I told you about. — colloquial resumptive: 'frá því' ('about it') keeps the dative slot filled. (The tighter written form pied-pipes the preposition: 'húsið sem ég sagði þér frá'.)
A crucial nuance, because a rigorous page must not overstate: for subjects and direct objects, Icelandic strongly prefers a gap, and inserting a resumptive there sounds wrong (*maðurinn sem hann kom "the man that he came" is bad). Resumptives are licensed precisely where the gap strategy fails or strains — the possessor, and oblique/embedded positions. For the possessive, the resumptive is obligatory; in deep oblique positions it is a colloquial option competing with preposition fronting. So the rule is not "use resumptives freely" but "use them where Icelandic has no gap to offer".
Infinitival relatives: "something to do"
Icelandic also forms relatives on an infinitive, corresponding to English "a book to read", "nothing to do", "someone to talk to". The frame is a (usually indefinite or quantified) head + að + infinitive, expressing a modal "available / suitable for X-ing".
Ég hef ekkert að gera í kvöld.
I have nothing to do tonight. — infinitival relative: 'ekkert að gera' = 'nothing [for one] to do'.
Hún fann sér rólegan stað til að lesa á.
She found herself a quiet place to read in. — infinitival relative with the goal-preposition frame 'til að … á'.
Það er nóg eftir að borða, fáðu þér bara.
There's plenty left to eat, just help yourself. — 'nóg … að borða' = 'enough to eat'; the infinitive carries the relative meaning.
These overlap in feel with English infinitival relatives, so the concept transfers; what does not transfer is the að (the infinitive marker) and the way a stranded preposition (að lesa *á* "to read in") attaches.
Why English speakers stumble here
The transfer traps are specific. English funnels free relatives through single wh-words (what, whoever, whatever, whose), so an English speaker's instinct is to look for one Icelandic word — and there isn't one. This breeds two errors: dropping sem after a wh-word (*hver vill koma for "whoever wants to come"), and reaching for a non-existent relative whose instead of the resumptive possessive construction. English also keeps the that/which distinction for restrictive vs non-restrictive; Icelandic uses sem for both and signals the difference only with commas and intonation. Master the demonstrative-plus-sem template and the resumptive-for-possessor rule, and the whole system falls into place.
Common Mistakes
❌ Hver vill koma má koma.
Missing 'sem' — a free relative needs the complementiser: 'hver SEM vill koma'. A bare wh-word can't head a free relative.
✅ Hver sem vill koma má koma.
Whoever wants to come may come.
The English wh-word whoever is one piece; Icelandic hver sem is two, and the sem is not optional.
❌ Ég skil ekki hvað þú meinar (as a free-relative object 'what you mean').
For 'what' as a free-relative argument, Icelandic prefers 'það sem': 'Ég skil ekki það sem þú átt við'. ('hvað' opens an indirect QUESTION, a subtly different meaning.)
✅ Ég skil ekki það sem þú átt við.
I don't understand what you mean. — 'það sem' = 'that which', the free relative.
English what is ambiguous between a free relative ("the thing that") and an embedded question; Icelandic splits them — það sem for the relative, hvað for the question.
❌ Þetta er maðurinn hvers nafn ég gleymdi.
There is no relative 'whose' in Icelandic — don't calque English 'whose'. Use a resumptive possessive: 'maðurinn sem ég gleymdi nafninu hans'.
✅ Þetta er maðurinn sem ég gleymdi nafninu hans.
This is the man whose name I forgot. — resumptive 'hans'.
There is no genitive relative pronoun; the possessor is expressed by a resumptive hans / hennar / þeirra inside the sem-clause.
❌ Maðurinn sem hann kom í gær er frændi minn.
Over-used resumptive — a SUBJECT relative takes a gap, not a resumptive pronoun: 'Maðurinn sem ___ kom í gær'. The 'hann' is wrong here.
✅ Maðurinn sem kom í gær er frændi minn.
The man who came yesterday is my cousin.
Resumptives belong only where there is no gap (possessor, deep oblique); for subjects and direct objects, use the gap.
❌ Bróðir minn sem býr í Noregi er flugmaður (intending the non-restrictive 'my brother, who lives in Norway').
If you have ONE brother, the relative is non-restrictive and needs commas: 'Bróðir minn, sem býr í Noregi, er flugmaður'. Without commas it restrictively implies you have several brothers.
✅ Bróðir minn, sem býr í Noregi, er flugmaður.
My brother, who lives in Norway, is a pilot. — non-restrictive, set off by commas.
Punctuation carries the restrictive/non-restrictive contrast that English marks with that vs which; the commas are not optional decoration.
Key Takeaways
- Icelandic has no single "whoever / what" word: a free relative is a declining demonstrative + invariant sem — sá sem "the one who", það sem "what / that which", þeir sem "those who", hver sem "whoever". The demonstrative takes the outer clause's case.
- hver/hvað sem is the free-choice "whoever / whatever (it may be)", often with a subjunctive verb because the referent is non-specific.
- Non-restrictive relatives are set off by commas and merely comment on an already-identified head; Icelandic uses sem for both restrictive and non-restrictive (no that/which split), and sem can take a whole clause as antecedent.
- Resumptive pronouns fill positions sem cannot relativise: the possessor (maðurinn sem ég gleymdi nafninu hans "the man whose name I forgot" — obligatory) and deep oblique slots (a colloquial option beside preposition fronting). Subjects and objects keep a gap, never a resumptive.
- Infinitival relatives (ekkert að gera "nothing to do") use a head + að
- infinitive.
- English funnels all of this through what / whoever / whose / that / which; Icelandic distributes it across the demonstrative-plus-sem template, resumptives, and commas.
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- The Relative Clause Marker sem (and er)A2 — The invariant Icelandic relativizer sem — the single word that covers English who, which and that for every gender, number and case — how the relativised noun's case is recovered from the gap, how prepositions strand, and the literary alternative er.
- Relative Clauses with semA2 — How relative clauses work in Icelandic — the invariant sem follows its head noun, the relativised role leaves a GAP whose case is recovered from inside the clause, prepositions STRAND at the end (húsið sem ég bý í), and possessive/oblique relatives often need a RESUMPTIVE pronoun (maðurinn sem bíllinn hans bilaði) where English uses 'whose'.
- sá, sú, það as PronounsB1 — The demonstrative sá / sú / það used pronominally — standing alone with no following noun: sá sem 'the one who', þeir sem 'those who', and það as the all-purpose neuter pronoun 'it / that' for things and whole clauses, including its genitive þess.
- Mood in Relative and Adverbial ClausesC1 — The subtle mood alternation inside relative and adverbial clauses, beyond the basic subjunctive triggers. A relative clause takes the subjunctive when its head is non-specific or hypothetical ('a man who knows Icelandic, any such man' → kunni) and the indicative when the referent is a specific, actual individual (kann). The same specificity logic reaches into temporal and purpose clauses. English marks this distinction only thinly, with 'any' versus 'the', so the mood must be built from scratch.
- Topicalization, Clefts, and FrontingB2 — The three constructions Icelandic uses to re-order a clause for emphasis: topicalization (fronting an object or adverb into the prefield with V2 inversion — Þennan mann þekki ég), the það er … sem cleft that isolates one focused element (Það var Jón sem kom), and stylistic fronting, the uniquely Scandinavian operation that fills an empty subject slot in a subordinate clause with any handy participle or adverb (þeir sem komnir eru), giving prose its formal, saga-flavoured ring.