citizen ● partner ● recruit ● scholar ● sponsor ● stewardObviously, a person can be a citizen, or a partner, or a recruit, or a scholar, or a sponsor, or a steward, but one of these six differs from the others in a fundamental way. Which one?
All correct answers will be acknowledged at the time of posting, but the comment(s) that include such correct answers will not be posted for a month from this date. If no correct answers are received during this period, this puzzle will remain unsolved indefinitely. I will not be providing the solution.
If you have found this one easy, then you should try An English Question, for which no correct solution has been submitted despite its having been posted almost two years ago. Rhyme Cryme, posted earlier this year, has also not been solved yet.
Correct solutions have been submitted below by an anonymous reader and by Siegfried, and by Claire via email. Only Siegfried has explained the reason for his answer.