Don’t make it a witch hunt! TIP: Which one do you need?!
Which is correct? “To our knowledge, it is the only body in the solar system which currently sustains life, although several other bodies are under investigation.” “To our knowledge, it is the only body in the solar system that currently sustains life, although several other bodies are under investigation.”
What are the differences in meaning? Who ate the cake that I bought this morning? Who ate the cake which I bought this morning? Any errors??
RULE (when referring to objects) THAT introduces a restrictive clause. –(no comma) WHICH introduces a non-restrictive or parenthetical clause. –(set in commas)
Test … Remove that / which clause. Does the meaning change? If yes, then clause is restrictive.
Gems that sparkle often elicit forgiveness. Diamonds, which are expensive, often elicit forgiveness.
Meaning changes … The painting that was hanging in the foyer was stolen. The painting, which was hanging in the foyer, was stolen. The Van Gogh that was hanging in the foyer, which we purchased in 1929 for $10 000, was stolen.
More … http://folk.uib.no/gmset/writing/practical_tips/that_which.html CGB’s Open Writing Lab http://folk.uib.no/gmset/writing/open_writing_lab.html