(a) General. Every person is competent to be a witness except as otherwise provided in these rules or by statute. (b) Minimal qualifications. A person is disqualified to testify as a witness if the trial court determines that he: (1) Lacked the capacity to perceive accurately the matters about which he proposes to testify; (2) Lacks the capacity to recollect facts; (3) Lacks the capacity to express himself so as to be understood, either directly or through an interpreter; or (4) Lacks the capacity to understand the obligation of a witness to tell the truth. Enacted 1990 Ky. Acts ch. 88, sec. 34; renumbered (7/1/92) pursuant to 1992; Ky. Acts ch. 324, sec. 34; Effective:July 1, 1992.