Yetas a linkingadverbgoesatthefrontof a clause, whereasstillgoesbeforeorjustafterthesubjectpronoun, forexample, hesayshe's vegetarian, yetheeatseverythingputinfrontofhim.
Buthestilleatseverythingputinfrontofhimnow, for, however, andnevertheless, whichemphasizecontrast, especiallyonewhichweexpecttosurprisethereaderorlistenerintermsofposition, theycancomeatthebeginning, middleorendof a clause, Althoughwetendtopreferthebeginning.