"Any" and "all" do have similar meanings, but you can't always simply replace "any" with "all" and retain the same meaning every time. "From any floor, you can

"Any" and "all" do have similar meanings, but you can't always simply replace "any" with "all" and retain the same meaning every time. "From any floor, you can use the fire escape to reach the ground" -> "It is true at all floors that you can use the fire escape to reach the ground". In this case you can replace "any" with "all" without changing the meaning; hypothetically one could interpret that to mean that while occupying all floors simultaneously you can use the fire escape to reach the ground, but since that's impossible (unless there's only a single floor) no one would interpret that sentence that way. "Ensure we have proper licensing for {any|all} software we depend upon". Again the meaning is preserved, because in this case "for all" is actually the more correct form. Every one will interpret "for any" correctly (as "for all"), but it could alternatively be interpreted to mean that you must have the license of at least one of said software. "Press any key, 3 times." -> "It is true of all keys that you can pick it and press it three times. Do so for one." Obviously the meaning changes if you just replace "any" with "all". A more subtle nuance is whether you're being asked to [press three times] [any key] or to [press any key] [three times]. "Aim to dress for any weather" -> "It is true of all weathers that you should aim to dress for it". This is the same case as the second example, it should have been "all". Otherwise there's an ambiguity that could be interpreted to mean that you should aim to dress for an arbitrary weather of your choosing. I would say that "any" when used in a declarative statement (such as your first example) means that the proposition is true for all members of the set under consideration. When used in an imperative statement (such as the other ones) sometimes will mean that you must apply the action to all members of the set, and sometimes that you're free to choose any subset and apply it to those. "Wash any dog" and "wash any dogs" and "for any dog, wash a cat" all mean different things.