The second gap is inside an "island," but the first "licit" gap makes the whole sentence feel okay to a native speaker.
Some researchers suggest the problem isn't grammar, but .
"*Who did [a picture of ___] hang on the wall?" (The phrase is the subject). Why Do Islands Exist? Islands
Once a subject moves to its final position, its internal structure is "frozen" and cannot be accessed.
Linguists debate whether these "walls" are built into our mental grammar or caused by how we process information. 1. The Architectural View The second gap is inside an "island," but
"Which book did you file ___ [without reading ___]?"
A occurs when the grammatical subject of a sentence acts as one of these barriers. In English, you can usually extract a word from the object of a sentence, but doing the same to the subject results in an ill-formed "island violation". Why Do Islands Exist
Not all subject islands are equally strong. Some violations become acceptable if they are "saved" by a second gap in the sentence, known as a .