its

 
Pronunciation: /ɪts/

possessive determiner

  • belonging to or associated with a thing previously mentioned or easily identified: turn the camera on its side he chose the area for its atmosphere
  • belonging to or associated with a child or animal of unspecified sex: a baby in its mother’s womb

A common error in writing is to confuse the possessive its (as in turn the camera on its side) with the contraction it’s (short for either it is or it has, as in it’s my fault; it’s been a hot day). The confusion is at least partly understandable since other possessive forms (singular nouns) do take an apostrophe + -s, as in the girl’s bike; the President’s smile.