Learn Hardcore Icelandic: Það er hættulegt að hjóla án hjálms. - It is dangerous to bike without a helmet.

Það – a dummy subject “it”, which is neuter singular nominative
hættulegt – adjective “dangerous” in the form that matches a neuter singular nominative subject

So:

masculine: hættulegur
feminine: hættuleg
neuter: hættulegt

Because það is neuter, the predicate adjective must be neuter too, so you get hættulegt.

If the subject were a real masculine noun, like sportið (“the sport”, actually neuter, but for illustration, imagine a masculine noun), the form would change. For example:

Hjólreiðar eru hættulegar – “Cycling is dangerous” (here hjólreiðar is feminine plural, so hættulegar is too)

What is the function of Það in this sentence? Is it referring to something specific?

Here Það is a dummy subject, like English “It” in:

“It is dangerous to cycle without a helmet.”

It does not refer to any specific thing. It’s just there because Icelandic, like English, usually likes having something in the subject position.

You can also put the infinitive clause first and keep the same meaning:

Að hjóla án hjálms er hættulegt.
“To cycle without a helmet is dangerous.”

So we have two equivalent options:

Það er hættulegt að hjóla án hjálms. (dummy subject first)
Að hjóla án hjálms er hættulegt. (infinitive clause as subject)

Both are correct and natural.

Is að in að hjóla the same að as in “to / at / by” in other contexts?

The word að can be several different things in Icelandic. In this sentence, it is the infinitive marker:

að hjóla – “to cycle / to ride a bike”

So here að = “to” (before a verb in its infinitive form).

Other common uses of að:

Preposition (often “to, at, by, towards”):
- Ég fer *að skólanum.* – “I go to the school.”
- Hún stendur *að dyrunum.* – “She stands by the door.”
Subordinating conjunction (like “that”):
- Ég veit *að þú kemur.* – “I know that you are coming.”

So yes, it’s the same word but with different grammatical roles. In að hjóla, you should think of it specifically as the infinitive “to”.

Why is it hjól*a (að hjóla) and not something like að hjól?

In Icelandic, many verbs are formed by adding -a to a noun or a stem.

hjól – “wheel” or “bike”
að hjóla – literally “to wheel”, but in modern usage: “to cycle / to ride a bike”

This pattern is common:

bíll (car) → að bíla (colloquial “to go by car / drive around”)
skíði (skis) → að skíða (to ski)

So hjóla is a regular -a verb in its infinitive:

að hjóla – to cycle
ég hjóla – I cycle
ég hjólaði – I cycled

What does án mean, and why does it make hjálmur change to hjálms?

Án means “without”.

In Icelandic, prepositions usually demand a specific case. Án always takes the genitive case.

The noun hjálmur (helmet) is masculine. Its singular forms are:

Nominative: hjálmur
Accusative: hjálm
Dative: hjálmi
Genitive: hjálms

Because án requires genitive, we must use hjálms:

án hjálms – “without a helmet”

So the structure is:

án + genitive → án hjálms

Why isn’t it án hjálmur or án hjálm?

Because of the genitive rule:

án always takes the genitive case, not nominative and not accusative.

Forms of hjálmur (singular, indefinite):

Nominative: hjálmur
Accusative: hjálm
Dative: hjálmi
Genitive: hjálms

So:

Incorrect: án hjálmur (nominative)
Incorrect: án hjálm (accusative)
Correct: án hjálms (genitive)

You’ll see the same with other nouns:

án penna (gen. sg. of penni – “without a pen”)
án peninga (gen. pl. of peningar – “without money”)

Could I say að hjóla án hjálms er hættulegt instead? Is the meaning different?

Yes, you can absolutely say:

Að hjóla án hjálms er hættulegt.

The meaning is essentially the same.

The difference is just word order and focus:

Það er hættulegt að hjóla án hjálms.
– Very close to English “It is dangerous to cycle without a helmet.”
– Uses a dummy subject (það) and puts the evaluation (hættulegt) early.
Að hjóla án hjálms er hættulegt.
– Literally “To cycle without a helmet is dangerous.”
– Puts the activity itself (að hjóla án hjálms) in the subject position.

Both are standard and natural in Icelandic.

Is hjól “bike” and hjóla “to bike”? How exactly are these related?

Yes, they are closely related:

hjól – literally “wheel”, but also commonly used for “bike”
að hjóla – “to cycle / to ride a bike”

The historical idea is “to wheel (along)”. In everyday modern Icelandic:

Ég á hjól. – “I have a bike.”
Ég hjóla í vinnuna. – “I bike to work.”

Sometimes speakers make it even more explicit:

að hjóla á hjóli – literally “to bike on a bike”

But often just að hjóla is enough and clearly means “to cycle”.

How do you pronounce hj in hjól, hjóla, hjálmur, hjálms?

The hj combination in Icelandic is usually pronounced as a voiceless palatal fricative /ç/ (similar to the German “ich” sound), followed by j-like quality.

Rough guide (in English terms):

hjól – roughly “hyole” with a soft hissy h at the front
hjóla – “HYOH-la”
hjálmur – “HYOWL-mur” (the á is like “ow” in “cow”)
hjálms – “HYOWL-ms”

The key point: hj is not just a simple English h + y, but a soft, fronted h-sound before j.

Why is the sentence Það er hættulegt að hjóla án hjálms and not something like Þú ert hættulegur að hjóla án hjálms?

In Icelandic, as in English, when you talk about an activity being dangerous in general, you usually use an impersonal structure, not a personal “you are dangerous”.

Það er hættulegt að hjóla án hjálms.
– “It is dangerous to cycle without a helmet.” (general statement)

If you said:

Þú ert hættulegur að hjóla án hjálms.

this would sound quite odd. It would literally mean something like:

“You are dangerous to cycle without a helmet.”

That suggests you are the dangerous thing, which is not the intended meaning.

To involve a specific person while keeping the structure natural, you might say:

Fyrir þig er hættulegt að hjóla án hjálms.
– “For you it is dangerous to cycle without a helmet.”

Why is hættulegt used and not some other form like hættulegur or hættuleg?

Because the adjective is agreeing with það, which is:

neuter
singular
nominative

So the adjective must be in neuter singular nominative, which is:

hættulegt

Other main forms of hættulegur:

masculine: hættulegur (e.g. maðurinn er hættulegur)
feminine: hættuleg (e.g. brúin er hættuleg)
neuter: hættulegt (e.g. það er hættulegt)

So in Það er hættulegt …, the -t is required by the neuter subject það.

Can án hjálms mean “without the helmet” as well as “without a helmet”?

Yes, án hjálms can mean either “without a helmet” (indefinite) or “without the helmet” (definite), depending on context.

Icelandic often leaves out the article where English uses a or the. The bare genitive hjálms can be interpreted either way:

generic / indefinite: “without a helmet (at all)”
specific: “without the helmet (we were talking about)”

If you really want to stress a specific, known helmet, you could say:

án hjálmsins – “without the helmet” (with the definite ending -ins)

But in everyday speech, án hjálms is normally understood as the general “without a helmet”.