PRONOUNS, PERSONAL. Thee for thou; after "to be"Thee for thou is also found after the verb to be, not merely in the Fool's mouth:
but also Timon:
“I would not be thee, nuncle.
“I am not thee.
where thee is, perhaps, influenced by the verb, "I fear," so that there is a confusion between "It is thou whom I fear" and "Thee I fear." In these cases thee represents a person not regarded as acting, but about whom something is predicated. Hence thou was, perhaps, changed to thee according to the analogy of the sound of he and she, which are used for "man" and "woman."
“It is thee I fear.