And you should talk less in general; almost everything you've said up to now could have been inferred from your behavior, even if you'd said only a few words, and it wasn't terribly favorable to you in any case. (1.7)
Have you ever felt that no matter what you say, you'll always be in the wrong? That's what K. is experiencing in a major way. Just by talking, he's sunk his case.
Then he went up the first set of stairs after all, his mind playing with the memory of the remark the guard Willem had made that the court was attracted by guilt, from which it actually followed that the room for the inquiry would have to be located off whatever stairway K chanced to choose. (3.6)
K. thinks he's in control here; whichever stairway he chooses will lead him to the court, because the world revolves around him. But it's actually the other way around: the court has infiltrated all of his options and controls what he can and cannot choose to do. It takes away his capacity for choice, to act as a free individual.
[W]hat has happened to me is merely a single case and as such of no particular consequence, since I don't take it very seriously, but it is typical of the proceedings being brought against many people. I speak for them, not for myself. (3.20)
K.'s pumping himself up here as a martyr for all the oppressed, but these grandiose claims really seem to be a way to mask his own feelings of insecurity in the courts, a world filled with threats he doesn't understand.
The faces that surrounded him! Tiny black eyes darted about, cheeks dropped like those of drunken men, the long beards were stiff and scraggly, and when they pulled on them, it seemed as if they were merely forming claws, not pulling beards. Beneath the beards, however – and this was the true discovery K. made – badges of various sizes and colors shimmered on the collars of their jackets. (3.28)
The critic Henry Sussman believes that this passage is reminiscent of a Talmudic academy, an institution devoted to the study of sacred Hebrew texts. That the court looks like a school filled with teachers, rather than students, contributes to K.'s feeling that he's being examined all the time.
While his trial rolled on, while the officials of the court were up there in the attic going over the trial documents, he was supposed to conduct bank business? Didn't that seem like a form of torture, sanctioned by the court, a part of the trial itself, accompanying it? (7.13)
The court's means include psychological torture, as well as the physical torture that K. witnesses in the scene with the flogger in Chapter 5.
One such superstition, for example, is that many people believe they can predict the outcome of the trial from the face of the defendant, and in particular from the lines of his lips. Now these people claimed that according to your lips, you were certain to be convicted soon. (8.4)
This superstition that Block relates to K. emphasizes K.'s isolation and certainly contributes to K.'s feelings of dread and paranoia. Even though it's merely a superstition, K. doesn't know what to believe or disbelieve because the court keeps overturning everything he takes to be common sense.
He pictured the vice president […] discovering errors, which K felt threatened by from a thousand directions as he worked, errors he could no longer avoid. (9.1)
K. starts to act more and more like Block as the novel progresses. By Chapter 9, he's the victim of Block's "senseless anxiety" (see Quote # 9 above), anticipating threats from every corner.