The following definitions apply under this Article:
(a) Statement. A "statement" is
(1) An oral or written assertion; or
(2) Nonverbal conduct of a person, if it is intended by him as an assertion.
(b) Declarant. A "declarant" is a person who makes a statement.
(c) Hearsay. "Hearsay" is a statement, other than one made by the declarant while testifying at the trial or hearing, offered in evidence to prove the truth of the matter asserted.
(d) Statements Which Are Not Hearsay. A statement is not hearsay if:
(1) Prior Statement By Witness. The declarant testifies at the trial or hearing and is subject to cross-examination concerning the statement, and the statement is (i) inconsistent with his testimony and, if offered in a criminal proceeding, was given under oath and subject to the penalty of perjury at a trial, hearing, or other proceeding, or in a disposition [deposition], or (ii) consistent with his testimony and is offered to rebut an express or implied charge against him of recent fabrication or improper influence or motive, or (iii) one of identification of a person made after perceiving him; or
(2) Admission By Party-opponent. The statement is offered against a party and is (i) his own statement, in either his individual or a representative capacity, (ii) a statement of which he has manifested his adoption or belief in its truth, (iii) a statement by a person authorized by him to make a statement concerning the subject, (iv) a statement by his agent or servant concerning a matter within the scope of his agency or employment, made during the existence of the relationship, or (v) a statement by a co-conspirator of a party during the course and in furtherance of the conspiracy.