Islands -
"Who did you see [a picture of ___]?" (The phrase is the object).
Extracting from a subject might simply be too mentally taxing for the brain to process in real-time. Exceptions and "Parasitic" Gaps Islands
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". "Who did you see [a picture of ___]
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 . In English, you can usually extract a word
Modern theories suggest certain phrases are "phases" that become invisible to the rest of the sentence once completed. 2. The Information Structure View
Some researchers suggest the problem isn't grammar, but .