Ein þvottaklemma datt af þvottasnúrunni, svo hún tók aðra úr vasanum.

Because þvottaklemma is a feminine noun.

The word einn meaning one changes for gender, number, and case:

• masculine: einn
• feminine: ein
• neuter: eitt

Here the noun is singular, feminine, and nominative, so the correct form is ein.

This also shows an important Icelandic pattern: there is no separate indefinite article like English a/an. Icelandic often just uses a bare noun, but einn/ein/eitt can be used when one or a certain one is relevant.

Not exactly.

Icelandic does not have a separate word that works exactly like English a/an. Instead:

• a noun can appear with no article at all
• or einn/ein/eitt can be used when the sense of one is important

So ein þvottaklemma is literally one clothespin, but in context it can sound very natural where English would simply say a clothespin.

It is a compound noun, which is extremely common in Icelandic.

Þvottaklemma = þvotta- + klemma

• þvottur = washing, laundry
• klemma = clip, clamp, pin

So þvottaklemma is literally a laundry-clip, i.e. a clothespin.

The same thing happens in þvottasnúra:

• þvotta- = laundry
• snúra = cord, line

So þvottasnúra means clothesline.

Datt is the past singular of the irregular verb detta, meaning to fall.

Some useful forms are:

• infinitive: detta
• present singular: dettur
• past singular: datt
• past plural: duttu

Since the subject is singular, ein þvottaklemma, the sentence needs the singular past form datt.

Because the preposition af takes the dative case here.

So:

• base noun: þvottasnúra = clothesline
• dative singular definite: þvottasnúrunni = the clothesline

The ending includes both:

1. the dative singular ending
2. the definite article meaning the

So af þvottasnúrunni means off the clothesline or from the clothesline.

This is very normal in Icelandic: the word for the is usually attached to the noun as a suffix rather than written separately.

Here svo means so, as in and so / therefore / so then.

It links the two parts of the sentence:

• one clothespin fell off the line
• so she took another from her pocket

In many contexts svo can also feel like then, especially in storytelling.

Because here svo is working as a conjunction meaning so, not just as a fronted adverb.

After a conjunction, normal clause order is fine:

• svo hún tók aðra...

If you used a fronted adverb like þá meaning then, Icelandic would normally show verb-second order:

• þá tók hún aðra...

So this sentence is behaving normally for svo used as so.

Grammatically, hún is the feminine singular pronoun, so a learner may notice that it could match þvottaklemma in gender.

But in this sentence, it clearly refers to a woman / she from the wider context, because of meaning:

• the clothespin took another from the pocket does not make sense
• she took another from the pocket does

So this is a good reminder that Icelandic pronouns match grammatical gender, but actual interpretation still depends heavily on context and meaning.

Tók is the past singular of taka, meaning to take.

Some useful forms:

• infinitive: taka
• present singular: tekur
• past singular: tók
• past plural: tóku

It is an irregular verb, so the stem changes.

Aðra means another here, and the noun is omitted because it is understood.

The full idea is:

• aðra þvottaklemmu = another clothespin

But Icelandic often leaves out a repeated noun when it is obvious, just like English can say she took another.

The form aðra is used because it is:

• feminine, to match þvottaklemma
• singular
• accusative, because it is the direct object of tók

A tricky point is that annar has irregular forms:

• nominative feminine: önnur
• accusative feminine: aðra

So tók aðra literally means took another one.

Because úr means out of / from, and it takes the dative case.

The noun is:

• vasi = pocket

Its dative singular definite form is:

• vasanum = the pocket

So:

• úr vasanum = out of the pocket / from the pocket

Again, the ending includes the definite article, so Icelandic expresses the pocket as one word: vasanum.

Because Icelandic usually uses a suffixed definite article.

Instead of a separate word like English the, Icelandic normally attaches the article to the noun:

• vasi = pocket
• vasinn = the pocket
• vasanum = to/from/in the pocket, depending on case and preposition

Likewise:

• þvottasnúra = clothesline
• þvottasnúran = the clothesline
• þvottasnúrunni = to/from/on the clothesline, depending on case and preposition

So when you see these longer forms, you are often looking at:

1. the noun
2. a case ending
3. the attached definite article

All packed into one word.