Possible Clues:

• Vague group creates idea that lacks alternative
• Hypothesis that has no alter­native for these people
• Designation on some pronoun pins
• Place for swimming lessons, informally
• He/___ pronouns
• With 20-Down, gender-neutral pronoun pair
• Third-person pronoun
• Your old relative finally accepted personal pronoun
• And, of course, ___ lived
• Third- or first-person pronoun