Hello Elia In the case of "His hospitalization lasted two days" "He was hospitalized for two days" both are correct ways of saying this, but "He was hospitalized for two days" is more commonly heard than "His hospitalization..." I would like to add even "He was hospitalized for two days" would be even less commonly heard than "He was in the hospital for two days" Of course, each of these statements mean the same thing, but the ways of saying it will vary according to the speaker. For instance: among hospital staff, doctors, etc you would hear "His hospitalization lasted two days" or "He was hospitalized..." Also in any type of formal statement; a news report or something you would hear it put that way. It's considered a more formal way of speaking. In everyday conversations you are more likely to hear "He was in the hospital for two days" El