801(a)-(c); 805, 806
PART F: HEARSAY
Exceptions. The exceptions are found in three rules. Rule 803 specifies twenty-three exceptions that apply whether or not the declarant is available. Rule 804 specifies five exceptions that apply only if the declarant is unavailable. Rule 807 recognizes a residual or “catch all” exception, under which some hearsay statements may be admitted on an ad hoc basis.
Exemptions. In addition to the exceptions, there were two categories of hearsay statements that the drafters wanted to admit into evidence. However, for theoretical reasons, the drafters choose not to classify them as exceptions. Instead, these statements were simply defined out of the definition of hearsay in Rule 801(d). The first category of exemptions (Rule 801(d)(1)) involves prior statements of a witness: It provides that certain prior inconsistent statements, prior consistent statements, and statements of identification are not hearsay. The second category (Rule 801(d)(2)) covers admissions of a party-opponent, of which there are five.
Cross-examination is the key to understanding the hearsay rule. If an out-of-court statement is offered for its truth, there is generally no cross-examination of the real witness (the declarant) to test that person’s perception, memory, narration, and sincerity. (The oath and observation of demeanor are ancillary safeguards to cross-examination.)
Hearsay can be defined as an out-of-court statement whose probative value depends on the credibility of the declarant. Such a "declarant-focused" definition highlights the underlying policy of the hearsay rule. There is, however, a competing definition, an "assertion-focused" definition: Hearsay is an out-of-court statement offered for the truth of its assertion. In most cases, the same result is reached under either definition but not always. The Federal Rules adopt the latter definition.
§ 31.04 Declarant Defined: FRE 801(b) 
Rule 801(b) defines “declarant” as a “person who makes a statement.” This definition makes clear that the hearsay rule does not apply to devices, such as radar, or to tracking dogs.
Rule 801(c) defines hearsay as a “statement, other than one made by the declarant while testifying at the trial or hearing.” Hence, an out-of-court (extrajudicial) statement does not lose its hearsay character simply because the declarant later becomes a witness at trial and testifies about the statement.
If the statement is offered for any purpose other than for its truth, it is not hearsay. This means that the hearsay character of the statement cannot be examined until we know why the proponent is offering the evidence - i.e., its relevancy. In other words, Rule 801 must be read along with Rule 401 (defining relevancy). In addition to Rule 401, Rule 403 plays an important role here.
Courts and commentators have recognized a number of recurring situations where statements are not offered for their truth. These are discussed below. Note, however, this is not an exhaustive list.
[A] To Show Effect on Listener
A statement offered to show its effect on the person who heard the statement is not hearsay - e.g., where the statement is offered to show only knowledge, good faith, or reasonableness.
[B] Verbal Acts
Statements that constitute verbal acts or operative acts are not hearsay because they are not offered for their truth. In other words, the uttering of certain words has independent legal significance under the substantive law – e.g., words of a contract, libel, slander, threats, and the like. Thus, we only care that these words were said, not that they are true.
[C] Verbal Parts of Acts
Verbal parts of acts are closely related to verbal acts. Such statements are offered in evidence only to show that they were made and to explain an otherwise ambiguous act. Most importantly, they must have independent legal significance.
[D] Prior Inconsistent Statements
The common law practice admitted prior inconsistent statements only for impeachment. Under this approach, the prior statement is offered to show the inconsistency between the witness's trial testimony and pretrial statements, rather than to show the truth of the assertions contained in the pretrial statement. In general, the Rules of Evidence maintain this distinction. There is, however, an important exception. See Rule 801(d)(1)(A).
[E] To Circumstantially Prove Declarant’s State of Mind
A person's mental state is often a material issue. If that person makes a statement that manifests her state of mind, the statement is relevant. Frequently, such statements are hearsay, but fall within the exception for presently existing state of mind. Rule 803(3). In other cases, the statement shows the declarant's state of mind only circumstantially. Under an assertion-oriented definition, the statement is not hearsay.
§ 31.07 Statement Defined; Implied Assertions: FRE 801(a) [415-20]
Rule 801(a) defines a “statement” as “(1) an oral or written assertion or (2) nonverbal conduct of a person, if it is intended by the person as an assertion.” Conduct is problematic. The critical distinction under the Federal Rules is between assertive and nonassertive conduct.
[A] Assertive Conduct
Sometimes people use conduct to communicate - e.g., nodding the head and pointing a finger. Rule 801(a) treats conduct intended as an assertion (assertive conduct) as hearsay.
[B] Nonassertive Conduct
Conduct that is not intended by the declarant to be an assertion (“implied assertions”) has divided courts and commentators. In Wright v. Doe D’ Tatham, 112 Eng. Rep. 488 (1837), the House of Lords declared such conduct hearsay, a position rejected by the Federal Rules.
The Due Process Clause may require the admissibility of hearsay in limited circumstances. The leading case is Chambers v. Mississippi, 410 U.S. 284, 302 (1973), in which the Supreme Court held that state evidentiary rules that precluded the admission of critical and reliable evidence denied the defendant due process. One of the rules in Chambers that made defense evidence inadmissible was the hearsay rule. According to the Court, “In these circumstances, where constitutional rights directly affecting the ascertainment of guilt are implicated, the hearsay rule may not be applied mechanistically to defeat the ends of justice.”
The trial judge decides the admissibility of hearsay evidence under Rule 104(a). Bourjaily v. United States, 483 U.S. 171, 175 (1987). Failure to raise the hearsay objection in a timely manner is a waiver of the objection (Rule 103), and the evidence may be considered by the jury for whatever probative value the jury wishes to give it.
§ 31.10 Double Hearsay: FRE 805 
Rule 805 governs the admissibility of multiple hearsay – i.e., hearsay within hearsay. If both parts of a double hearsay statement fall within an exception, the statement is admissible.
§ 31.11 Calling Hearsay Declarants: FRE 806 [421-22]
Rule 806 provides that, if a party against whom a hearsay statement is admitted calls the declarant as a witness, that party may examine the declarant “as if under cross-examination.”
§ 31.12 Impeachment & Rehabilitation of Declarants: FRE 806 [422-23]
Rule 806 also governs the impeachment and rehabilitation of hearsay declarants. In effect, a hearsay declarant is a witness and generally may be impeached in the same manner as trial witnesses.
The Rules of Evidence avoid the use of the term "res gestae," a confusing phrase which encompasses both evidence that is not hearsay and evidence that is hearsay but may fall within several exceptions to the hearsay rule.