If the spray head is built in to the main faucet then there would be no threads to hook to.
If the spray head is a separate thing off to the side then you can unscrew the aerator (little round ring hanging down from the end of the faucet) and attach a faucet hose adapter.
I was confused at first because we don't have the built in kind and I wondered why it wouldn't work with a wort chiller.
Thank you for clearing that up - I was just thinking today that it made no sense that I couldn't still use my main kitchen faucet with an adaptor as long as my spray head was a separate attachment off to the side - then this response. Much appreciated - wort chiller here I come.