4 “I solemnly affirm that the evidence that I shall give, shall be the truth, the whole truth and nothing but the truth.” (2) Such affirmation shall have the same legal force and effect as if the person making it had taken the oath. (3) The validity of an oath duly taken by a witness shall not be affected if such witness does not on any of the grounds referred to in subsection (1) decline to take the oath. 164 When unsworn or unaffirmed evidence admissible (1) Any person, who is found not to understand the nature and import of the oath or the affirmation, may be admitted to give evidence in criminal proceedings without taking the oath or making the affirmation: Provided that such person shall, in lieu of the oath or affirmation, be admonished by the presiding judge or judicial officer to speak the truth. (2) If such person wilfully and falsely states anything which, if sworn, would have amounted to the offence of perjury or any statutory offence punishable as perjury, he shall be deemed to have committed that offence, and shall, upon conviction, be liable to such punishment as is by law provided as a punishment for that offence.’ The reason for giving evidence under oath (s162), affirmation (s163) or admonishment (s164) is to ensure that the evidence given is reliable.2 [5] Section 192 of the Criminal Procedure Act declares generally that unless specially excluded all persons are both competent and compellable witnesses. A witness is competent to testify if his or her evidence may properly be put before the court. If a child does not have the ability to distinguish between truth and untruth, such a child is not a competent witness.3 It is the duty of the presiding officer to satisfy himself 2 See Director of Public Prosecutions, Transvaal v Minister of Justice and Constitutional Development & others 2009 (2) SACR 130 (CC) para 166. 3 S v L 1973 (1) SA 344 (C) at 348A–C; Alfred V. Lansdown and Jean Campbell South African Criminal Law and Procedure vol 5 at p 740.