sadly
Word family
Synonym discussion
Sense: adverb/2
These four words all express regret about a situation but differ in formality and emotional weight. Unfortunately is the most neutral and by far the most common in both speech and writing; it fits nearly any context. Sadly carries a slightly warmer, more personal sense of disappointment — it sounds less distant than 'unfortunately' when the speaker shares the sadness. Regrettably is more formal and detached, often appearing in official statements or business correspondence. Alas is literary or humorous in modern English and rarely used in serious writing. For example: 'Unfortunately, the train was delayed.' (neutral fact); 'Sadly, the old cinema will close next month.' (personal loss); 'Regrettably, your application was unsuccessful.' (formal rejection); 'Alas, our hero arrived too late.' (storybook tone).
Etymology
From Old English sæd meaning 'sated, full' and also 'weary,' which gradually shifted in Middle English to mean 'sorrowful.' The -ly suffix was added to form the manner adverb. The sentence-adverb sense meaning 'unfortunately' developed in the 1600s, as speakers began using 'sadly' to comment on whole situations.