I read a comment on licensing in another post, which made me revisit this concept. Unfortunately I haven't got access to CaGEL – only to its "little brother", Huddleston and Pullum's A Student's Introduction to English Grammar (henceforth referred to as H&P), so this is what I will refer to in the following.
In their discussion of licensing (e.g. pp65ff), H&P repeatedly use a test where they substitute the head of a VP with another verb, in order to illustrate the difference between complement and adjunct. For instance, they show on p65 that the NP the cheese in Sue used the cheese is a complement (Od) because if the head of the VP (used) is substituted with an intransitive verb – i.e. a verb that doesn't license a complement – we get an ungrammatical result: * Sue disappeared the cheese. On p71 they do the same thing with the manager, in Ed told the manager, showing that the manager is a complement since it is inadmissible with the intransitive verb arrive – * Ed arrived the manager.
To me, this MO seems odd, seeing that it suggests that a certain form always has the same function, regardless of the context in which it is used – something that obviously doesn't hold true. The unreliability of the substitution test becomes blatantly obvious if we use it on a clause such as She stayed in her bedroom, where we want to determine whether in her bedroom is a complement or not. If we use this test here, and substitute the head of the VP (stayed) with the intransitive verb disappeared, we get She disappeared in her bedroom, which is a perfectly well formed sentence. According to the test, then, in her bedroom should be an adjunct; however, according to H&P (p142) in her bedroom is, in fact, a complement in the VP stayed in her bedroom.
So, my question now is quite simply: have I missed something here? Is there a way the substitution test is, in fact, reliable as a way of determining licensing and, thereby, whether a certain element is an adjunct or a complement?
Any thoughts on this would be greatly appreciated.
(for a related question, please see this)