Questions & Answers about Það er erfitt að velja íþrótt.
In this sentence, Það is a dummy subject, just like “it” in English in sentences like “It is hard to choose a sport.”
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”).
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.