Learn Hardcore Icelandic: Það er erfitt að velja íþrótt.

It does not refer to any particular thing (not to the sport, not to the situation). Icelandic, like English, usually needs a subject, so Það er… is used as a neutral way to say “It is…” when the real “subject” is the whole action að velja íþrótt (“to choose a sport”).

Why is the adjective erfitt in the neuter form and not something like erfiður?

Erfitt is the neuter singular form of the adjective erfiður (“difficult, hard”).

Because Það here is a dummy subject and is grammatically neuter singular, the adjective must agree with it in gender and number. So:

Það er erfitt… = It is hard… (impersonal, with dummy Það)
Verkið er erfitt. = The task is hard. (verk is neuter → erfitt)
Leikurinn er erfiður. = The game is hard. (leikur is masculine → erfiður)
Æfingin er erfið. = The exercise is hard. (æfing is feminine → erfið)

In your sentence, to sound natural and grammatical, it has to be erfitt with Það.

What is the að before velja? Is it the same as English “to”?

Yes, here að is the infinitive marker, similar to English “to” in “to choose.”

velja = “choose” (bare infinitive)
að velja = “to choose”

This að is different from að used as a preposition (“to, towards, at”) or as a conjunction (“that”). In this sentence, you can recognize it as the infinitive marker because it comes directly before a bare verb form (velja).

What kind of verb is velja? Is it regular? How is it conjugated?

Velja is an irregular strong verb. You don’t need all forms at once, but here are the most common present and past forms:

Infinitive: að velja – to choose
1st person singular present: ég vel – I choose
2nd person singular present: þú velur – you choose
3rd person singular present: hann/hún/það velur – he/she/it chooses
1st person plural present: við veljum – we choose
Past singular: ég valdi – I chose
Past plural: við völdum – we chose*
Past participle (m./f./n.): valinn / völin / valið – chosen

In your sentence you only see the infinitive: að velja = to choose.

Why is íþrótt in this form? Why not something like íþróttir or a different case?

Íþrótt is a feminine noun, and here it is:

singular
indefinite (no article like “the”)
in the accusative case

The verb velja (“choose”) takes a direct object in the accusative. For feminine nouns like íþrótt, the nominative and accusative singular forms happen to be the same: íþrótt.

So:

að velja íþrótt = to choose a sport (object in accusative)
If you wanted plural: að velja íþróttir = to choose sports / to choose some sports (accusative plural).

There is no article like English “a” or “the”; that information is usually inferred from context.

Could I also say “Að velja íþrótt er erfitt”? Is that correct, and is there any difference?

Yes, Að velja íþrótt er erfitt is fully correct Icelandic and means the same thing: “To choose a sport is hard.”

Það er erfitt að velja íþrótt. – more natural, impersonal, like English “It is hard to choose a sport.”
Að velja íþrótt er erfitt. – grammatically fine, slightly more formal or “written,” like English “To choose a sport is hard.”

Both are correct; in everyday speech, the Það er erfitt… pattern is more common.

Can I drop Það and just say “Er erfitt að velja íþrótt”?

Not in standard Icelandic.

You normally need the dummy subject Það in this construction. Just saying Er erfitt að velja íþrótt sounds incomplete or ungrammatical, except possibly as a very clipped, colloquial follow‑up in conversation.

For a full sentence, you should say:

Það er erfitt að velja íþrótt.

How would I say “It is hard for me to choose a sport”?

You can keep the same structure and just add fyrir mig (“for me”):

Það er erfitt fyrir mig að velja íþrótt.
= It is hard for me to choose a sport.

Somewhat more advanced / more “Icelandic-sounding” alternatives exist (using dative experiencers), but fyrir mig is clear and natural for a learner.

What is the pronunciation of the tricky letters in this sentence (ð, þ, á, ó)?

Very roughly (using English-like hints):

Það – [θaːð]
- Þ/þ at the start: like th in thing.
- ð at the end: like th in this (voiced).
- á: a long “ow” as in now, but a bit tenser.
er – [ɛr] (short e like in bed, then r rolled or tapped)
erfitt – [ˈɛrˌfɪht] (r rolled; tt pronounced with a little h‑like puff)
að – [að] (same voiced ð as in this, but word often very short or reduced in fast speech)
velja – [ˈvɛlja] (lj is like ly in million)
íþrótt – [ˈiːθrout]
- í: long ee like see.
- þ again like th in thing.
- ó: long o like in go, but a bit tenser.

You don’t have to be perfect, but it helps to focus on þ [θ] and ð [ð], since English uses them but spells them with th.

Is there a general pattern in Icelandic for saying “It is ADJECTIVE to VERB” like this?

Yes. A very common pattern is:

Það er + [adjective in neuter singular] + að + [infinitive]

Examples:

Það er auðvelt að læra þetta.
It is easy to learn this.
Það er skemmtilegt að lesa bækur.
It is fun to read books.
Það er erfitt að velja íþrótt.
It is hard to choose a sport.

So you can reuse this pattern with many adjectives and infinitives.