[Nightedge]

Could I use to have?

-John had been informed _____ the prize.

If yes, it could be more succinct than 'that he would have', etc. But I am not sure whether it's OK.

[susan53]

No. Inform someone that or inform someone about would be fine, but you can't follow inform with an infinitive :

John was informed about winning the prize
John was informed that he had won the prize

Inform is a bit formal though. If this were a formal context it's unlikely that you'd just use a first name. Better - tell


John was told about winning the prize.
John was told that he'd won the prize.

[Nightedge]

Excellent answer. Thank you.