=>It was hidden. (Ex: "The book was hidden." AND "He intentionally hid the book / He hid the book on purpose" )
=>Engagement の日本語はなんですか。(I know that "marriage" is 結婚 and during someone's marriage ceremony we can congratulate the persons saying "結婚式おめでとうございます！". How to congratulate someone when they get engaged with each other, like saying "Congratulations on your engagement!")
=> Also, is "翻訳してください" a proper way of saying "Please translate"? Or, are there better sentences for this? Please teach me if there are.