In this article
Translation is written: a translator turns a document from one language into another. Interpretation is spoken or signed: an interpreter conveys what someone says, live, in another language. They are separate skills with separate credentials, and many professionals specialize in one.
Side by side
| Translation | Interpretation | |
|---|---|---|
| Works with | Written text, from documents to websites | Speech or sign language, as it happens |
| Timing | Hours to weeks, with time to research and revise | Live, with seconds to choose words |
| Main forms | Standard translation; certified translation with a signed statement of accuracy | Consecutive (in turns), simultaneous (at the same time), and sight translation (reading a document aloud in another language) |
| U.S. credentials | American Translators Association certification, by language pair and direction | Federal and state court interpreter certification, CCHI and NBCMI medical certification, RID certification for ASL |
| Typical work | Contracts, medical records, birth certificates, immigration documents, websites | Depositions, hearings, medical visits, meetings, phone and video calls |
Interpreters are booked for a date, a time and a place or video link. Translations are scheduled by deadline. For either, tell the provider the language and regional variety, the subject matter and how the work will be used, such as a court filing, a medical record or a public notice, because that decides which credential the job needs.
How interpreters work
- Consecutive interpreting: the speaker pauses and the interpreter renders each segment. It is the standard mode for witness testimony at depositions. See consecutive vs. simultaneous interpreting.
- Simultaneous interpreting: the interpreter speaks while the speaker is still talking, often through headsets. Long proceedings use a team so interpreters can rotate. See interpreter teams for long proceedings.
- Remote interpreting: by video or phone, which suits short or urgent sessions better than long, document-heavy ones. See when video remote interpreting works.
- Sign language interpreting is interpretation too. Some Deaf people also need a Certified Deaf Interpreter working with a hearing interpreter. See when a CDI is needed.
How translators work
A professional translation usually passes through at least two people: a translator, then a second linguist who revises it against the original. The ISO 17100 standard for translation services requires that revision step. Translators generally work into their native language, keep glossaries of each client's terms, and use software that stores past translations so wording stays consistent across documents.
Because translation is not live, it can be checked, revised and certified. That is why courts, immigration authorities and hospitals accept certified translations of records but rely on qualified interpreters for live testimony and conversations.
Which one do you need?
- Someone has to understand or speak at a live event, a deposition, a hearing, an exam or a meeting: book an interpreter.
- A document has to exist in another language, a contract, a record or a certificate: order a translation. For documents submitted to USCIS, 8 CFR 103.2(b)(3) requires a full English translation that the translator certifies as complete and accurate, plus the translator's certification that they are competent to translate from the foreign language into English. See certified vs. notarized translation.
- A document has to be read to someone during a live event: the interpreter sight translates it. See sight translation of exhibits at depositions.
- A recording in another language has to become evidence: that is transcription and translation. See foreign-language audio evidence.
Common mix-ups
- "Translator" is often used for interpreters. In court and in medicine the difference matters, because the credentials are different.
- "Simultaneous translation" usually means simultaneous interpreting, done live in a booth or with headsets.
- Being bilingual is not the same as being an interpreter or a translator. See bilingual staff vs. certified interpreters.
- Machine translation tools translate text; they do not interpret, and their accuracy varies sharply by language. See what machine translation studies found.
How AMS handles both
AMS books certified interpreters for depositions, hearings and medical-legal exams and handles certified document translation. See legal interpreting or request a quote with the language, date and document type.