Sec. 48. General rule. — The opinion of witness is not admissible, except as indicated in the following sections. 

 Sec. 49. Opinion of expert witness. — The opinion of a witness on a matter requiring special knowledge, skill, experience or training which he shown to posses, may be received in evidence.

 Sec. 50. Opinion of ordinary witnesses. — The opinion of a witness for which proper basis is given, may be received in evidence regarding —

 (a) the identity of a person about whom he has adequate knowledge;

 (b) A handwriting with which he has sufficient familiarity; and

 (c) The mental sanity of a person with whom he is sufficiently acquainted.

The witness may also testify on his impressions of the emotion, behavior, condition or appearance of a person. (Rule 130, Rules of Court)


Is the opinion of a witness admissible in evidence? 

General rule: NO. The opinion of a witness is not admissible.
Reason: The opinion of the witness has no relevance to the case.


When is opinion of a witness is admissible?

The opinion of a witness is admissible:
  1. On a matter requiring special knowledge, skill, experience or training (SKET) which he is shown to possess, that is, when he is an expert thereon;
  2. Regarding the identity of a person about whom he has adequate knowledge;
  3. Regarding the handwriting of a person with which he has sufficient familiarity or when he is an expert witness;
  4. On the mental sanity of a person with whom he is sufficiently acquainted or if the latter is an expert witness; (Because, chances are, if one knows the person very well, he will be the first one to detect some changes in the person. Witness need not be expert in Psychiatry)
  5. On the emotion, behavior, condition or appearance of a person (ABCE) which he has observed;
  6. On ordinary matters known to all men of common perception such as the value of ordinary household articles (Galian vs. State Assurance Co., 29 Phil. 413).

Bar Question:

Q: At Nolan’s trial for possession and use of the prohibited drug, known as “shabu", his girlfriend Kim, testified that on a particular day, he would see Nolan very prim and proper, alert and sharp, but that
three days after, he would appear haggard, tired and overly nervous at the slightest sound he would hear. Nolan objects to the admissibility of Kim’s testimony on the ground that Kim merely stated her opinion without having been first qualified as expert witness. Should you, as judge, exclude the testimony of Kim? (Bar 2005)

A: No. The testimony of Kim should not be excluded. Even though Kim is not an expert witness, Kim may testify on her impressions of the emotion, behavior, condition or appearance of a person. (Sec. 50, last par., Rule 130).