Question 1
Is the interpreter who covered the deposition automatically right for trial?
Not automatically. Deposition work is almost entirely consecutive interpretation between a deponent and counsel in a conference room, with the record held by a reporter. Trial adds three things that deposition does not require: simultaneous interpretation delivered quietly to the client at counsel table while the proceeding continues, sworn witness testimony interpreted on the record in front of the bench and the jury, and sight translation of documents handed up during examination. An interpreter can be excellent in the first setting and untested in the other two. Ask the agency directly whether the individual has interpreted witness testimony at trial in that venue, and treat continuity from the deposition as a benefit rather than a qualification on its own.
Question 2
How many interpreters does a multi-day trial actually need?
For anything beyond a short hearing, plan for two interpreters who rotate. Simultaneous interpretation is cognitively intense and accuracy degrades measurably after roughly thirty minutes of continuous work, which is why team interpreting is the recognised professional standard for trials, multi-day hearings, and extended proceedings. A single interpreter asked to cover a full trial day will either request breaks that interrupt the proceeding or continue past the point where the record is reliable. If the client also needs interpretation at counsel table while a different witness testifies, that is a second simultaneous channel and usually a second interpreter regardless of duration. Confirm team size when the trial date is set, not the week before. Our note on the NAJIT team interpreting guideline sets out where the standard comes from.
Question 3
Does the difference between court-certified and registered matter at trial?
Yes, and it is the distinction most often missed when a firm books by language alone. California credentials interpreters as certified or registered, and the difference is the examination: a certified language requires the Written Exam plus the Bilingual Interpreting Exam, while a registered language requires the Written Exam plus Oral Proficiency Exams. Spanish, Mandarin, Cantonese, Korean, Arabic, Farsi, Russian, Portuguese, Punjabi, Vietnamese, Eastern Armenian and Filipino are certified; French, Japanese, German, Italian and many others are registered. Registered is a different credential, not a lesser interpreter. Which designation applies depends on the language, and the venue decides what it will accept. A language that is certified in one state may have no certification pathway in another. Before booking, ask which designation exists for that language pair and have the agency put the interpreter's designation in writing. Our note on how language and venue decide who can take the assignment covers how this plays out in practice.
Question 4
Who interprets for the witness, and who interprets for the client at counsel table?
These are two separate roles and conflating them is a common scheduling error. The witness interpreter works on the record, is sworn, and interprets testimony consecutively so the reporter can capture it. The interpreter at counsel table works simultaneously and quietly so the client can follow the proceeding as it happens, including argument and testimony from other witnesses. One person cannot do both at once, and courts generally will not pause proceedings so a single interpreter can switch roles. When your client will be present throughout and will also testify, tell the agency both facts at booking so the assignment is staffed correctly from the start.
Question 5
What has to happen with foreign-language exhibits before trial?
Documents that will be offered as exhibits need certified written translation prepared and served in advance, with a certificate of accuracy. Handing an interpreter a document at the podium and asking for a sight translation is appropriate for a short passage read into the record, but it is not a substitute for a translated exhibit, and opposing counsel can reasonably object. Identify every foreign-language document in the exhibit list as early as possible, because certified translation of a long or technical document takes time and rushing it is where errors enter. This differs from deposition practice, where sight translation of an unexpected document is more routine; our page on court exhibits in another language sets out what actually gets admitted.
Question 6
How far ahead should a trial interpreter be booked, and what if the date moves?
Book as soon as the trial date is set, and tell the agency the date is provisional. The certified bench in any given language and county is small, and in less common languages it can be a handful of people who are also covering other courts. Waiting until the final status conference frequently means the available interpreter is the one nobody else booked. Trial dates move constantly, so ask the agency at booking how they handle a continuance and how much notice they need, and get that in writing rather than assuming. A firm that books early and reschedules once is in a far stronger position than a firm that books late and finds no coverage.
Question 7
What should the interpreter receive before the trial date?
At minimum: the case caption and venue, the language and specific regional variant, the expected length and whether the client will be present throughout, the names of parties and witnesses so the interpreter can check for any conflict, and a glossary of technical or industry terms that will come up. In technical matters, the pleadings and any expert reports materially improve accuracy. None of this is a courtesy. An interpreter who sees an unfamiliar technical term for the first time during cross-examination is being set up to fail, and the cost of that lands on the record. Agencies should provide confidentiality commitments in writing before any case material is shared.
