οὗ

Determine by context:

• (rel. adv.) ’in which place, where’
• Gen Sg of ὅς, ἥ, ὅ ’of whom, of which’
  2nd Sg Dat of ύ ’of you’
  3rd Gen Sg refl. ’of him, her, it’
• (adv.) ’there, where’