question on can + be + past participle

[iconoclast]

Happy to oblige, woodcutter. As noted, 'can be trained' is broken down into modal auxiliary plus base passive infintive, which latter consists of infinitive 'be' plus past participle 'trained'. This holds for "true" passives like the example I gave, which, expanded for clarification, could read "These dogs can easily be trained by an experienced handler".

Obviously, the parsing of participial adjectives is different, e.g. "He used to be interested in training dogs". I don't know how uncommon a view this is, or even that it should be seen as uncommon, for it's a simple, uncontroversial application of rule. In other words, if "Dogs are trained by experienced handlers" is true passive, then so is my first example. And if "He's interested in training dogs" is 'be' plus participial adjective, then so is my second example. Hope this clarifies.