The reason court interpreters are important in legal proceedings is because they're going to make sure that the person who is the court participant whether they are a witness, a juror, a litigant, they're going to make sure that they understand the proceedings fully, as if the individual spoke the English language fluently.

It is even more important when an individual is representing themselves and they cannot speak the English language fluently enough to understand the court proceedings that the judge actually make the determination whether or not they need an interpreter, because, otherwise, the individual is not going to understand the proceedings, is not going to understand what evidence to present to the court, what questions to ask of a witness, how to cross examine a witness, and if they don't understand the proceedings, then all that's likely going to do is delay your court room docket, because you're going to have to repeat these proceedings over and over again.

Rules 1-103(B)(5)  and 5-122(B)(5) Court must appoint an interpreter if the court perceives the need for an interpreter.