Capitalization
Personal pronouns are not normally capitalized, except in particular cases. In English the first-person subject pronoun I is always capitalized, and in some Christian texts the personal pronouns referring to Jesus or God are capitalized (He, Thou, etc.).
In many European languages, but not English, the second-person pronouns are often capitalized for politeness when they refer to the person one is writing to (such as in a letter).
For details, see Capitalization: Pronouns.
Read more about this topic: Weak Pronoun