Multiple choice

The woman over there, ______, was my teacher.

  1. when wearing a hat

  2. while wearing a hat

  3. who's wearing a hat

  4. whose wearing a hat

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Who's is a contraction of who is, which is required here to describe the woman. Whose is a possessive pronoun, and the other options do not fit the grammatical structure.