LogFAQs > #971252532

HM's are gone in S/V (all traversal abilities are tied to the cover legendary, who joins you almost immediately and periodically gets new abilities as you feed it sandwiches). TM's are still there, but you can now create copies of any that you've already found at will in exchange for a few resources that are fairly easy to farm. There are still a whole lot of restrictions on who can learn what TM's that you really can't know without consulting external resources (unless you're a glutton for trial and error), but that's to be expected because letting anyone learn anything would be a mess, and I'd say it's generally a pretty good system now in that you're no longer dealing with a cripplingly finite resource and you don't have to worry as much about screwing Pokemon up by not taking the right abilities on levelling up.