What age must a child be before they can speak in the court of law in Vermont?

There is no minimum age for a child to testify in court in Vermont. In fact in most states there is no minimum age. Whether the judge would be willing to hear the testimony of a minor child depends on the case and what type of testimony as there are two types.

Factual Testimony is when someone testifies to what they personally witnessed (saw, heard, felt, tasted, etc.). If a minor is a witness in a case, the judge will very likely assign an attorney for the minor so that they will be protected by someone whose sold job it is to think of what's best for the child, not the defense or plaintiff or prosecutor. At that point the judge will ask questions of the child (either in chambers or in the courtroom - possibly during pre-trial motions, or the trial itself) to see if he/she understands the difference between truth and lies, that there would be punishment for lying in court, and to see if the child's testimony would cause them more harm than do good for whomever they are testifying. If a child is a victim of a crime, protecting the child from testifying of it would case the child harm is common as it is felt to be better to err on the side of caution, then to let a child who is not emotionally or mentally ready to testify, relive the abuse in court. That said children as young as age four have been found competant by judges in regards to factual testmony.

Preference Testimony is when someone is testifying to say what they wish the judge would do, or let them do. This is very common in divorce court and like factual testimony, the judge may have an attorney appointed to the minor, and ask questions to determine competency. And like in factual testimony, if the judge decides the child cannot testify they need to say on the record why and how they came to that decision. If they do not, it can be cause for appeal.

As you have not mentioned what kind of case or type of testimony, I suggest you consult with an attorney in Vermont (many give a free consultation) to discuss the case you want to testify in and how likely it would be in your particular situation.