The rest of the team hung back to talk to one another as usual at the end of practice, but Harry headed straight back to the Gryffindor common room, where he found Ron and Hermione playing chess. Chess was the only thing Hermione ever lost at, something Harry and Ron thought was very good for her.
(Harry Potter and the Sorcerer’s Stone)
‘Something’ looks alike to complementizers, for example ‘that’ or ‘what’ or ‘which’. But I can’t find this usage in dictionaries. What role does ‘something’ take in this context?
The word something in this case refers to losing. The sentence could be rewritten as:
Chess was the only thing Hermione ever lost at, and Harry and Ron thought it was very good for her to lose at something.
Source : Link , Question Author : Listenever , Answer Author : J.R.