The Adjunct Island Effect (AIE) is often attributed to something like an
Adjunct Island Condition, stating that adjuncts are islands for extraction.
I argue instead that the AIE is a property of the internal structure of
certain PPs (regardless of their status as "arguments" or "adjuncts").
There are three parts to my argumentation. First, I show that simple PPs
(i.e. those with a non-clausal, NP complement) are normally not islands,
including both "argument" and "adjunct" PPs. Second, I show that tensed
clausal PP "adjuncts," which often are islands, remain islands even when
recast as "arguments." Third, I show that the same holds for gerundive PPs;
these tend to be weak islands, but this property characterizes gerundive PP
"adjuncts" and gerundive PP "arguments" alike. I conclude that the AIE is
the result of the internal structure of PP, rather than being a result of
the PP’s external syntax (i.e. whether it is an "argument" vs. an
"adjunct").
