Learn Hardcore Icelandic: Stundum er erfitt að einbeita sér.

Underlyingly, the structure is like: (Það) er erfitt að einbeita sér.
– það = “it” (dummy subject)
In everyday Icelandic, this dummy það is usually dropped when the “real” subject is an infinitive clause (að einbeita sér).

So:

Stundum er erfitt að einbeita sér.
≈ “Sometimes it is hard to concentrate.”

You can say Stundum er það erfitt að einbeita sér, but the það is optional and not needed.

What exactly does stundum mean, and what form is it?

Stundum means “sometimes”.

Grammatically:

stund = “a short while, a moment” (a noun)
stundum is the dative plural form of stund, used adverbially.
Many Icelandic time nouns in the dative plural become adverbs of frequency:
- dagur → dögum (í gamla daga, etc.)
- stund → stundum (“at times” → “sometimes”)

Useful related adverbs:

oft – often
sjaldan – seldom, rarely
aldrei – never

So stundum er erfitt… = “Sometimes it is hard…”

Why is erfitt in the neuter form, and not erfiður or erfið?

Icelandic adjectives agree in gender, number, and case with what they describe.

The basic adjective here is erfiður, erfið, erfitt = “hard, difficult”:

masculine: erfiður
feminine: erfið
neuter: erfitt

In this sentence, erfitt is describing the whole situation að einbeita sér (“to concentrate”), which is treated as a neuter subject (comparable to the dummy það, which is neuter).

So:

Það er erfitt. – “It is hard.” (neuter það → erfitt)
Verkefnið er erfitt. – “The task is hard.” (verkefni is neuter)
Stundum er erfitt að einbeita sér. – “Sometimes it is hard to concentrate.” (understood neuter “it / situation”)

That’s why you get erfitt, not erfiður/erfið.

What is the role of að before einbeita, and is it the same að as “that”?

Here að is the infinitive marker, like English “to” in “to concentrate.”

að einbeita sér = “to concentrate (oneself)”

Icelandic að can be:

Infinitive marker (not stressed, before a verb):
- að einbeita sér – to concentrate
- að læra – to learn
Subordinating conjunction “that”:
- Ég veit að þú kemur. – “I know that you’re coming.”
Preposition “to / at / towards” (different usage again):
- að dyrunum – at the door

In Stundum er erfitt að einbeita sér, it’s clearly the infinitive marker: it just signals that einbeita is in the infinitive, like English “to.”

Why do you say að einbeita sér instead of just að einbeita? What does sér do?

The verb að einbeita sér is a reflexive verb in Icelandic. Literally, it’s “to concentrate oneself.”

einbeita always takes a reflexive pronoun as its object:
- Ég einbeiti mér. – I concentrate (myself).
- Þú einbeitir þér. – You concentrate (yourself).
- Hann / hún einbeitir sér. – He / she concentrates (himself / herself).
- Við einbeitum okkur. – We concentrate (ourselves).
- Þið einbeitið ykkur. – You (pl.) concentrate (yourselves).
- Þeir / þær / þau einbeita sér. – They concentrate (themselves).

So the natural dictionary form is að einbeita sér, not just að einbeita.

In the sentence:

að einbeita sér = “to concentrate (oneself / oneself in general)”
sér is the 3rd person reflexive pronoun in the dative case (see next question).

Why is it sér and not sig here?

Because einbeita takes the dative case, and sér is the dative reflexive form.

Reflexive pronoun forms (3rd person, “himself / herself / themselves”):

Accusative: sig
Dative: sér
Genitive: sín

Some verbs “take” accusative objects, some dative, some genitive. The verb að einbeita sér always uses dative:

að einbeita sér – to concentrate (lit. “concentrate oneself” in the dative)
Present tense:
- Ég einbeiti mér. (first-person dative)
- Hann einbeitir sér. (third-person dative)

If the verb instead took accusative, then you would see sig:

að þvo sig – to wash oneself (accusative)
- Hann þvær sig. – He washes himself.

So einbeita sér is fixed with sér, not sig, because of dative government.

If I’m talking specifically about myself, could I say Stundum er erfitt að einbeita mér instead of sér?

In theory, yes, að einbeita mér is grammatically fine (1st-person dative). But in this exact construction it sounds odd in normal Icelandic.

The original sentence is impersonal and general:

Stundum er erfitt að einbeita sér.
– “Sometimes it is hard to concentrate.” (in general, for people)

If you want to talk specifically about your difficulty, Icelandic speakers usually change the structure instead of just swapping sér for mér. More natural options:

Stundum á ég erfitt með að einbeita mér.
“Sometimes I have trouble concentrating.”
Stundum finnst mér erfitt að einbeita mér.
“Sometimes I find it hard to concentrate.”

So:

að einbeita sér is the normal generic phrasing in the impersonal sentence.
Use mér with a different structure when you really want a personal statement.

Can I say Að einbeita sér er stundum erfitt instead? Is that still correct?

Yes, it’s perfectly correct:

Að einbeita sér er stundum erfitt.
≈ “To concentrate is sometimes hard.” / “Concentrating is sometimes hard.”

Differences in feel:

Stundum er erfitt að einbeita sér.
– Adverb stundum (sometimes) comes first; the sentence starts with time, then “is hard,” then the action.
Að einbeita sér er stundum erfitt.
– The action (“to concentrate”) is fronted and emphasized as the topic.

Both are grammatical. Native speakers use both; the first one might sound a bit more casual and common in everyday speech.

Could I also say Stundum er það erfitt að einbeita sér with það? What’s the difference?

Yes, that is also correct:

Stundum er erfitt að einbeita sér.
Stundum er það erfitt að einbeita sér.

Meaning: essentially the same – “Sometimes it is hard to concentrate.”

Nuance:

Without það:
– Slightly more neutral and natural in everyday speech. The dummy “it” is just left unspoken.
With það:
– Can sound a bit more emphatic or explicit, or sometimes a bit more formal or careful.
– You might especially keep það if you want to stress that particular difficulty:
- Stundum er það erfitt að einbeita sér, sérstaklega þegar...
  “Sometimes it is hard to concentrate, especially when…”

In many cases, Icelanders will simply drop það in this kind of impersonal sentence, as in the original.

How would I put this sentence in the past, or talk about it as a habit?

You mainly change the verb vera (“to be”) and keep the infinitive clause the same:

Present:
- Stundum er erfitt að einbeita sér.
  “Sometimes it is hard to concentrate.”
Past:
- Stundum var erfitt að einbeita sér.
  “Sometimes it was hard to concentrate.”
Future-ish (using munu):
- Stundum mun vera erfitt að einbeita sér.
  “Sometimes it will be hard to concentrate.”

For habit in the past, context carries that meaning, just like in English:

Þegar ég var barn, var oft erfitt að einbeita sér í skólanum.
“When I was a child, it was often hard to concentrate at school.”

The að einbeita sér part stays in the infinitive; only er → var / verður / mun vera changes.

How are the main words here pronounced roughly?

Very roughly, in an English-friendly approximation:

Stundum – [STOON-dum]
- u like “oo” in book, but shorter; nd is clear.
er – [ehr]
- Like “air” but short and closed.
erfitt – [EHR-fit]
- Stress on the first syllable; tt is a bit like English ht in light in many accents, but you’ll be understood with simple [t].
að – between [ath] and very soft [aðh]
- ð is like the th in “this”, but often very soft or almost silent before another consonant.
einbeita – [EIN-bay-ta]
- ei like “ay” in day; stress on EIN.
sér – around [syer] / [s-yehr]
- é is like “yeh” in yes but lengthened; r is tapped or rolled.

These are only approximations, but they can give you a starting point before listening to native audio.