Sulfur dioxide (SO@sub 2@) is infamous for its role as an environmental pollutant and in most circumstances a catalyst poison. Over the past twenty years SO@sub 2@ has been investigated on a number of single crystal metal surfaces, yet there is little SO@sub 2@/Cu(110) work. The results of our study which combines STM and TPRS to advance the understanding of the reactions of SO@sub 2@ on Cu(110) are reported. STM images reveal the formation of c(2x2), p(2x2) and c(4x2) surface structures when SO@sub 2@ interacts with the clean Cu(110) surface. The p(2x2) and c(4x2) structures form small domains, approximately 3-4 lattice units across, while the c(2x2) structures are considerably larger. The LEED pattern resulting from this reaction is a diffuse c(2x2), consistent with the domain sizes revealed by STM. STM studies of the dissociative adsorption of D@sub 2@S on Cu(110) reveal a c(2x2) sulfur structure on the surface with a corrugation identical to that observed upon SO@sub 2@ interaction with the Cu(110) surface, indicating that the c(2x2) moieties are due to sulfur adsorption. The p(2x2) and c(4x2) moieties are distributed randomly throughout the scan area in equal proportions, and STM shows similar corrugations of these two phases suggesting that they are the same SO@sub x@ species, stable up to 450 K (determined) by separate TPRS experiments. With the use of isotopic labeling the TPRS work suggests that the SO@sub x@ species is SO@sub 3@, with SO@sub 3@ bound to the surface via one of its oxygen atoms. This stoichiometry is consistent with the 1:2 ratio of the fraction of the surface covered by S and SO@sub x@ when the clean surface is exposed to SO@sub 2@. Further, from our STM images the binding site for the SO@sub 3@ can be determined to be a four-fold hollow. With our STM we have also probed the mobility of surface species. The real-time movie reveals the mobility of both SO@sub 3@ and oxygen rows along the [001] and [110] azimuths, respectively.