The adverb: it marks the whole sentence, telling the reader "what comes next is what you would expect". "Unsurprisingly, the train was late again." It sits at the front of a sentence far more often than anywhere else, and it works like a signpost — the writer is saying "I know you already guessed this", which builds a quiet agreement with the reader before the fact is even given. That is why it is so common in news writing, reports and essays. Two other positions exist: in the middle ("the plan, unsurprisingly, went nowhere"), and after "not" for a soft double negative ("not unsurprisingly" — though careful writers avoid this, since it usually just means "unsurprisingly" and the extra "not" only muddies things). Like the adjective, it often carries dry criticism: "Unsurprisingly, nobody had read the contract." It is close in meaning to "of course", "naturally" and "predictably", but softer than "predictably", which usually sounds annoyed. In speech, Taiwanese students can safely use "not surprisingly" instead — it means the same and sounds a little more relaxed.