I sat awhile in perfect silence, rallying my stunned faculties. Immediately it occurred to me that my ears had deceived me, or Bartleby had entirely misunderstood my meaning. I repeated my request in the clearest tone I could assume; but in quite as clear a one came the previous reply, "I would prefer not to." (20)
This strange interaction demonstrates the essential problem of language in this story – it's both immensely powerful and incredibly futile. Bartleby's statement has an almost physical impact on the Narrator, but it doesn't necessarily communicate anything clearly.
"Will you tell me anything about yourself?"
"I would prefer not to."
"But what reasonable objection can you have to speak to me? I feel friendly towards you."
He did not look at me while I spoke, but kept his gaze fixed upon my bust of Cicero, which, as I then sat, was directly behind me, some six inches above my head.
"What is your answer, Bartleby?" said I, after waiting a considerable time for a reply, during which his countenance remained immovable, only there was the faintest conceivable tremor of the white attenuated mouth.
"At present I prefer to give no answer," he said, and retired into his hermitage. (60-61)
This passage demonstrates the unsatisfactory nature of communication via language in this story – Bartleby's refusal to speak is tantamount to a refusal to be human at all.
Somehow, of late, I had got into the way of involuntarily using this word "prefer" upon all sorts of not exactly suitable occasions. And I trembled to think that my contact with the scrivener had already and seriously affected me in a mental way. And what further and deeper aberration might it not yet produce? (66)
The irresistible spread of Bartleby's distinctive style of speaking – especially his favorite word – shows us what a powerful marker of influence language can be at times, even when we don't realize it.
As he opened the folding door to retire, Nippers at his desk caught a glimpse of me, and asked whether I would prefer to have a certain paper copied on blue paper or white. He did not in the least roguishly accent the word prefer. It was plain that it involuntarily rolled from his tongue. I thought to myself, surely I must get rid of a demented man, who already has in some degree turned the tongues, if not the heads, of myself and clerks. (68)
Again, we see language as an interesting symptom of whatever mental illness Bartleby is spreading through the office.
"The time has come; you must quit this place; I am sorry for you; here is money; but you must go."
"I would prefer not," he replied, with his back still towards me.
He remained silent. (76-77)
Bartleby proves here that sometimes the most effective mode of communication is simply silence.
"I know you," he said, without looking round – "and I want nothing to say to you." (122)
Huh – for the first time, Bartleby's language directly expresses something. He doesn't just say he prefers not to speak to the Narrator, but clearly says that he doesn't want to. This subtle change surely expresses a change in Bartleby himself…