alas is an interjection used to express sorrow or disappointment. It works as a commentary to whatever statement or situation preceded it and is typically interjected after an unfortunate event or otherwise unfortunate turn of events.
alas is typically found after an unfortunate event or comment, emphasizing disappointment or sorrow. It is not typically used to describe some sort of happy ending to an event, though it could be used in a sarcastic tone in this situation.
1. 'He failed the test, alas.'
2. 'I thought our team could make it to the championship, alas, it was not meant to be.'
3. 'Alas, I have to go back to work already.'
be sure to insert it into the sentence in a way that emphasizes the precedingly stated point (sad, unfortunate, etc.). Additionally, avoid using alas in situations that signal a happy ending.