Section 725 ILCS 5/115-14 - Witness Competency(a) Every person, irrespective of age, is qualified to be a witness and no person is disqualified to testify to any matter, except as provided in subsection (b).(b) A person is disqualified to be a witness if he or she is:(1) Incapable of expressing himself or herself concerning the matter so as to be understood, either directly or through interpretation by one who can understand him or her; or(2) Incapable of understanding the duty of a witness to tell the truth.(c) A party may move the court prior to a witness' testimony being received in evidence, requesting that the court make a determination if a witness is competent to testify. The hearing shall be conducted outside the presence of the jury and the burden of proof shall be on the moving party.