allur, hálfur, báðir: 'all', 'half', 'both'

English keeps "all," "half," and "both" as small, mostly unchanging words — you just plant them in front of a noun. Icelandic does not give you that ease: allur ("all, whole"), hálfur ("half"), and báðir ("both") are fully inflected words that agree with their noun in gender, number, and case, exactly like adjectives. Two of them also do surprising double duty: neuter bæði is not only "both" but the conjunction "both … and," and allt is the everyday standalone word for "everything." This page covers these three totality quantifiers — how they decline, where they sit, and the traps an English speaker keeps stepping in. (Partitive and negative quantifiers like sumir "some" and enginn "no/none" are treated separately.)

allur — "all" in the plural, "whole" in the singular

allur has one form-set but two readable senses, sorted by number. In the plural it means "all" — allir menn "all men," allar konur "all women," öll börn "all children." In the singular it means "the whole" — allan daginn "the whole day," alla nóttina "all night long," allt landið "the whole country." Same word, and the singular/plural split does the semantic work, just as English "all day" (whole) sits beside "all the days" (every one).

Crucially, allur declines for gender, and its forms carry the famous u-umlaut: the feminine and neuter plural nominative is öll (a → ö), and the neuter singular is allt. Here is the core paradigm.

Two orthographic points to nail. The u-umlaut rounds a → ö exactly where an -u- (or the bare feminine/neuter ending) demands it: öll (f. sg. and n. pl.), öllum (dat.), öllu (n. dat. sg.). But the masculine accusative singular keeps its a: allan (allan daginn), never \öllan. And the neuter singular is *allt with -llt.

Notice allan daginn versus allir nemendur: the first is singular "whole," the second plural "all." Same lemma, two senses, sorted by number — and the umlaut surfaces in öll börnin but not in allan daginn.

allt — the standalone "everything"

The neuter singular allt does double duty: beyond "the whole (thing)," it is the ordinary standalone pronoun "everything." Allt er í lagi "everything's fine," ég sá allt "I saw everything," allt eða ekkert "all or nothing." This is one of the most frequent words in the language, so flag it: when allt stands alone with no noun, read it as "everything," and remember it stays neuter singular and declines (allt, allt, öllu, alls).

báðir — "both," plural-only and tied to the definite

báðir means "both," and it is structurally unlike English "both" in two ways. First, it exists only in the plural — there is no singular báðir, because "both" is inherently about two. Second, it normally pairs with a definite noun: you say báðir bræðurnir ("both the brothers," with the suffixed article -nir), báðar systurnar ("both the sisters"), bæði börnin ("both the children"). The noun carries the definite article even though English "both brothers" does not. The neuter is the eye-catching form: bæði (with æ).

The genitive beggja is irregular and worth memorising on its own (beggja vegna "on both sides / for both reasons"). Note that all three genders share báðum in the dative and beggja in the genitive; gender only separates the nominative and accusative.

bæði … og — "both … and" (the conjunction)

Here is the double duty to flag hardest. The neuter bæði is also the first half of the correlative conjunction bæði … og "both … and," joining two coordinated elements: bæði þú og ég "both you and I," bæði kalt og blautt "both cold and wet." This is not the quantifier modifying a noun — it is a connective pairing two phrases, and it stays the fixed form bæði regardless of what it links. Recognising which job bæði is doing is purely a matter of structure: before a single (definite) noun it is the quantifier "both (the) …"; framing two coordinated items with og between them, it is the conjunction "both … and."

hálfur — "half"

hálfur ("half") is an adjective-like quantifier that agrees in gender, number, and case: hálfur tími "half an hour" (masc.), hálf flaska "half a bottle" (fem.), hálft glas "half a glass" (neut.). The neuter is hálft and the feminine hálf. It precedes the noun and inflects with it, so unlike English invariant "half," you must match it. The common time expression hálf þrjú literally means "half three" but, on the Germanic clock pattern, means half-past two (i.e. "half [toward] three") — a genuine trap worth flagging.

Common Mistakes

Key Takeaways

• allur, hálfur, báðir all agree in gender, number, and case — they are not invariant like English "all / half / both."
• allur = "all" in the plural (allir, öll), "the whole" in the singular (allan daginn). Watch the u-umlaut: öll, öllum, öllu — but masc. acc. sg. stays allan.
• allt standing alone = "everything" (allt er í lagi).
• báðir is plural-only and normally takes a definite noun: báðir bræðurnir, bæði börnin. Neuter = bæði; genitive = irregular beggja.
• Neuter bæði is also the conjunction bæði … og "both … and."
• hálfur = "half," fully inflected (hálfan, hálf, hálft); hálf þrjú = half past two.