In James's The Turn of the Screw, the governess is trapped on an old estate in which reality feels turned upside down. The writer uses literary devices to makes the reader feel as confused and lost as the governess does as she questions what is real around her.
A primary way in which James does this is with clever use of imagery and setting. The reader never fully has a grasp of the layout of the mansion or the grounds, and James's descriptions always evoke an eerie sense of quiet, particularly during meetings with Quint. The governess describes "dead silence" during one of their interactions, giving the scene a sense of unease.
Frequent nautical references also convey a sense of the governess feeling stranded, or abandoned out at sea, with nowhere to go for help. The governess describes herself as being at the helm of "a great drifting ship" and sees images of Miles drowning.
Additionally, diction is incredibly important. James often chooses vague language over concrete language, which gives the reader a sense of frustration and uncertainty. The reason for Miles's expulsion from school is never explicitly given, and the nature of Quint and Jessel's relationship is similarly defined in extremely vague terms. Conversations between characters are frequently extremely vague as well. This is done by James in order to make the reader feel a weird sense of uncertainty about what is going on, and to make the reader constantly question his or her understanding of the situation.
This is exactly the governess's situation. She has a constantly changing understanding of what is going on in the mansion, and her ever-shifting perspective is part of what drives her to madness. Similarly, the literary devices employed by James make us feel uneasy, confused, and frustrated as the story continues. Our relationship with the novel is the same as the governess's relationship to her situation, and this is primarily communicated through the use of literary devices such as imagery and diction.