Best Practices When Working with an Interpreter

For any criminal matter in which a defendant has limited ability to speak or understand English, the Interpreters Office will provide the best available simultaneous interpreters for every court proceeding. Interpreters will also be made available for witnesses who testify in a language other than English. The mission of the Interpreters Office is to provide the court with smooth, unobtrusive, and unassailably accurate interpretation or translation (written texts) as needed.

Yet even experienced interpreters can only be as effective as circumstances permit. Judges and courtroom deputies play a key role in promoting the best possible delivery of interpretation services by ensuring a suitable working environment.


Audibility conditions in the courtroom are of paramount importance. Interpreters have to listen in one language and speak in another, while  analyzing incoming information, all at the same time. Because an interpreter is duty bound to interpret everything said in court, omitting nothing, the interpreter's ability to hear the proceedings is as important as the court reporter's. What cannot be heard cannot be interpreted. An interpreter needs to be positioned in the place that allows for optimal hearing.  This may change during the same proceeding, since each speaker has different diction and delivery. All courtroom microphones should be used, including the one at the bench, to provide for optimal audibility. The interpreter's microphone has a long cord so that the interpreter can change position as needed.

Team Interpreting

For any proceeding over an hour, interpreters work in teams to keep the information flow at a consistent rate of accuracy. Interpreters process an average of 150-200 words a minute, and mental efficiency inevitably flags after a certain amount of time on task. Studies have shown that concentration and accuracy decrease markedly after 30 to 40 minutes if an interpreter works without relief. When working at the witness stand as well, especially if the testimony is lengthy, interpreters should rotate for periodic relief.

Most of the time, no one will even realize the interpreters are there, and the parties can engage in the normal flow of exchange without making any adjustments. Even while processing highly accelerated rates of speech, interpreters will rarely interrupt court proceedings. If they do, it is because a word or phrase could not be heard.

At Trial: What a Judge Can Do

  • Remind the parties and witnesses to speak clearly into the microphones. Assure the interpreters that if they request it, anything unintelligible can be repeated.
  • Ask the prosecutor or the deputy to provide interpreters with a copy of the indictment.
  • Before trial gets underway, establish ground rules for any challenge to the interpretation to be taken up at sidebar, with the interpreter to be included. The party challenging the interpretation has the burden to show it was mistaken.
  • Instruct the jury regarding the function of interpreters, i.e. that they work for the court and not for a particular side in a case. Instruct the jury that they are not to be concerned with questions of interpretation.
  • Inform the parties that any request for an interpreter should be made with a minimum of 24 hour notice.

Witness Testimony

Recommendation: Instruct defense attorneys to advise the Interpreters Office one to two days ahead of time if they need an interpreter for a witness. The Office also needs to know the estimated length of each witness's testimony.

By law [ the Court Interpreters Act, 28 USC 1827 ] the U.S. Attorney's Office provides interpreters for government witnesses. All other witnesses will be assisted by the court interpreter.

When interpreting for a witness, an interpreter does consecutive, not simultaneous interpretation. That means that Q and A through an interpreter will take more time, because the interpreter waits until the question is complete before interpreting it into the foreign language, and then waits for the foreign-language answer to be finished before interpreting it back into English.


In order for the Interpreters Office to assign interpreters and plan scheduling of many other court proceedings, timely notification is essential.


The worst-case scenario for all concerned is when an interpreter is requested at the last minute, mid-trial, with a witness already on the stand and the judge and jury waiting. Neither the interpreter nor the home office knows who the parties are, what the case is about or how long the testimony may last. The more unfamiliar the interpreter is with the subject matter of a witness's testimony, the more room there is for contextual error. A witness may pronounce names, dates, places or other references in a hurried or sloppy manner, and the resulting confusion may not only lessen the witness's credibility but also affect the interpreter's accuracy and composure. Planning ahead will eliminate these occurrences.

Conflicts of Interest

Recommendation: If legal argument about an interpreter conflict arises, the judge may simply inquire of the interpreter if he or she is under oath to interpret well and truly, completely and impartially. If the answer is in the affirmative, the judge may instruct the interpreter to proceed regardless of what the parties may perceive as a conflict.

An interpreter has the obligation to inform the parties of any previous out-of-court contact with the case.

Whereas attorneys sometimes consider it a conflict of interest for an interpreter to interpret for both defense and prosecution witnesses, it is not unusual for this to occur, especially with lesser-known languages in which interpreters are hard to find. Interpreters are sworn to interpret accurately, fairly and impartially, no matter for whom they are interpreting. Thus, once under oath, an interpreter may work for either or for both sides at the direction of the court. 

An interpreter on a case should not be a witness for either side. Only the judge may ask for an expert opinion regarding a matter of interpretation or language.

Interaction and Protocol with the Court

On the rare occasion when an interpreter, despite a natural reticence to interrupt the proceedings, requests permission to speak or to clarify something., it will be done in the third person so as not to confuse the record. ("The interpreter would request...")

For example, an interpreter needs to bring it to the court's attention if:

  • A word or phrase the witness uses is unfamiliar or ambiguous and cannot be translated without further inquiry;
  • Unspecified pronouns make the subject of the sentence unclear (singular or plural, male or female);
  • A reference is unintelligible or slurred pronunciation not fully understood;
  • The witness is attempting to engage in ex parte conversation and needs to be instructed not to speak to the interpreter ; or if the witness answers before objections are ruled on and needs to be instructed as to when to answer. 

On rare occasions, an interpreter may ask to approach the bench if something needs to be brought immediately to the judge's attention. For example:

  • The witness speaks an unfamiliar language or dialect;
  • Specialized subject matter is beyond interpreter's competence;
  • A correction needs to be made of previously interpreted testimony;
  • An uninvited interaction with a juror has taken place;
  • A problem arises that seriously compromises the accuracy of the interpretation, or the fairness of the trial (eg., a material error in a foreign language document or tape transcript).

Correcting the Record

Interpreters always use judgment and common sense in choosing from among several possible interpretations of a phrase. Context is always crucial to one's interpretation and word choices. An occasional error is inevitable, because an interpreter cannot be as fully aware of the context as the witness. In addition, some witnesses do not fully express what they mean.

In the event of a sidebar to discuss alleged erroneous interpretations, judges should keep in mind that attorneys are not language experts and have particular interests at stake.

An interpreter should correct a mistake as soon as possible, lest the error be compounded, but is never supposed to correct mistakes made by the questioner or witness. Hesitation or ambiguity in the original are necessarily reflected in the interpretation.

An interpreter will let the judge know if there is a need to correct a previous interpretation and follow the judge's instructions regarding stating the correction for the record.

Resource Information

Publications available online:

For a judge's checklist on managing interpreters during trial, see:

For a view from the bench of interpreting issues, see: