Breakdown of Voitko arvata, onko kysymys vaikea?
olla
to be
vaikea
difficult / hard
voida
can, to be able to
kysymys
question
Questions & Answers about Voitko arvata, onko kysymys vaikea?
Why is there a "-ko" at the end of both Voitko and onko?
This sentence actually contains two questions! The first -ko is in Voitko (Can you) to make the main sentence a direct yes/no question. The second is in onko (is it) to form the indirect question. When English uses "if" or "whether" for an indirect question, Finnish attaches the -ko/-kö ending to the verb instead.
Could I use the word jos (if) to say "if the question is difficult"?
No, you cannot. In Finnish, jos is only used for conditions (like "If it rains, I will stay home"). When "if" means "whether" in an indirect question (like "Can you guess whether..."), you must use the -ko/-kö ending. Here, it is attached to on (is) to make onko.
Why is there a comma before onko?
In Finnish punctuation rules, you almost always separate clauses with a comma. The first part (Can you guess) and the second part (if the question is difficult) both have their own verbs, so they are separate clauses. Therefore, a comma is required after arvata.
Why does the verb arvata (to guess) stay in its dictionary form here?