Reassuringly is the adverb: you do something in a way that makes people feel less worried or frightened.

Reassuringly是 the adverb副詞：you do something你做某件事 in a way的方式 that makes people feel less worried or frightened讓人比較不擔心或不害怕。

She smiled reassuringly. He spoke reassuringly to the child.

She她 reassuringly安撫地 smiled笑了笑。He他 reassuringly安撫地 to the child對孩子 spoke說話。

Writers also put it at the front of a sentence to comment on the whole fact: “Reassuringly, the door was still locked.” That means “this next thing should make you feel safer.” Though actually, it is more at home in writing than in quick talk. In conversation people often just smile and say “Don’t worry.” If you already know the adjective reassuring, this word is that idea turned into “in a reassuring way.” It does not add a new meaning; it only changes how the word sits in the sentence.

Writers作者 also也會 put it at the front of a sentence把它放在句首，to comment on the whole fact用來評論整件事："Reassuringly, the door was still locked."「Reassuringly, the door was still locked.」（值得安心的是，門還是鎖著的）That means意思是 "this next thing should make you feel safer"「接下來這件事應該會讓你比較安心」。Though actually不過其實，it is more at home in writing than in quick talk這種用法比較常出現在寫作裡，口語很少這樣講。In conversation在對話裡，people often just smile and say人們通常只是笑一笑說 "Don't worry."「別擔心」。If you already know the adjective reassuring如果你已經知道形容詞 reassuring，this word這個字 is就是 that idea turned into把那個意思變成 "in a reassuring way"「以令人安心的方式」。It它 does not add a new meaning沒有加上新的意思；it only changes只是改變了 how the word sits in the sentence這個字在句子裡的位置。