Subjective experiences are experienced only by the person who has it. No one else could. A person who has a subjective experience could try to express it through Language, but he will never transmit the experience no matter how good he communicates it. The exact knowledge he had through the subjective experience is his and his alone. Knowledge cannot be transmitted. Language can only trigger existing patterns in someone else’s brain.
To understand this theory easily, think of this scenario.
Two people are looking at the sunset. The sunset is an objective reality, part of an objective external physical world (an external objective physical world exists). The proof of this is that both people see it. However, while they are looking at the same objective reality, both people do not have the same subjective experience. If one of them is color blind, he might see the sun’s color in a different way than the other person.