Written English uses some conventions that are different than spoken English. One of these is the convention of not shifting person. In speech, people tend to shift easily from "I" to "you" to "he" and so on as they talk. Neither listeners nor speakers even notice.
However, in Standard Written English (the English of school essays and such), the rule is that we should select a person and pretty much stick to him, her or it throughout, unless the logic of what you are saying forces you to change. For example, I have just shifted from "we" to "you," and then to "I."
More correctly, the above sentences could be written:
However, in Standard Written English (the English of school essays and such), the rule is to select a person and pretty much stick to him, her or it throughout, unless the logic of what is being said requires a change. For example, the above sentence has just shifted...