What is correct face to face or face-to-face?
It depends on how it being used. As an Adjective: Face-to-face, as in “I had a face-to-face encounter with Bigfoot!” Here, “face-to-face” is used as an adjective to describe the noun “encounter.”–what sort of encounter. As a Adverb: Face to face, as in “I met face to face with the company president today.” Here face to face is used to modify the verb “met”–how I met the president. I guess the only way I remember this is that an adjective is often only one word: red balloon, fast car, big house) so the hyphens sort of make the phrase one word –if that works for you. Another example would be: Our meetings should start on time. We must strive to have on-time meetings.