Interpreters and translators typically do the following:

• Convert concepts in the source language to equivalent concepts in the target language
• Compile information and technical terms into glossaries and terminology databases to be used in their oral renditions and translations
• Speak, read, and write fluently in at least two languages, one of which is usually English
• Relay the style and tone of the original language
• Render spoken messages accurately, quickly, and clearly
• Apply their cultural knowledge to render an accurate and meaningful interpretation or translation of the original message

Interpreters and translators aid communication by converting messages or text from one language into another language. Although some people do both, interpreting and translating are different professions: interpreters work with spoken communication, and translators work with written communication.

Interpreters convert information from one spoken language into another—or, in the case of sign language interpreters, between spoken language and sign language. The goal of an interpreter is to have people hear the interpretation as if it were the original language. Interpreters usually must be fluent speakers or signers of both languages, because they communicate back and forth among people who do not share a common language.

There are three common modes of interpreting: simultaneous, consecutive, and sight translation:

• Simultaneous interpreters convey a spoken or signed message into another language at the same time someone is speaking or signing. Simultaneous interpreters must be familiar with the subject matter and maintain a high level of concentration to convey the message accurately and completely. Due to the mental fatigue involved, simultaneous interpreters may work in pairs or small teams if they are interpreting for long periods of time, such as in a court or conference setting.
• Consecutive interpreters convey the speaker’s or signer’s message in another language after they have stopped to allow for the interpretation. Note taking is generally an essential part of consecutive interpreting.
• Sight translation interpreters provide translation of a written document directly into a spoken language, for immediate understanding, but not for the purposes of producing a written translated document.

Translators convert written materials from one language into another language. The goal of a translator is to have people read the translation as if it were the original written material. To do that, the translator must be able to write in a way that maintains or duplicates the structure and style of the original text while keeping the ideas and facts of the original material accurate. Translators must properly transmit any cultural references, including slang, and other expressions that do not translate literally.

Translators must read the original language fluently. They usually translate into their native language.

Nearly all translation work is done on a computer, and translators receive and submit most assignments electronically. Translations often go through several revisions before becoming final.

Translation usually is done with computer-assisted translation (CAT) tools, in which a computer database of previously translated sentences or segments (called a “translation memory”) may be used to translate new text. CAT tools allow translators to work more efficiently and consistently. Translators also edit materials translated by computers, or machine translation. This process is called post-editing.

Interpretation and translation services are needed in virtually all subject areas. Although most interpreters and translators specialize in a particular field or industry, many have more than one area of specialization.

The following are examples of types of interpreters and translators:

Community interpreters work in community-based environments, providing vital language interpretation one-on-one or in group settings. Community interpreters often are needed at parent–teacher conferences, community events, business and public meetings, social and government agencies, new-home purchases, and many other work and community settings.

Conference interpreters work at conferences that have non-English-speaking attendees. The work is often in the field of international business or diplomacy, although conference interpreters can interpret for any organization that works with speakers of foreign languages. Employers generally prefer more experienced interpreters who can convert two languages into one native language—for example, the ability to interpret from Spanish and French into English. For some positions, such as those with the United Nations, this qualification is required.

Conference interpreters often do simultaneous interpreting. Attendees at a conference or meeting who do not understand the language of the speaker wear earphones tuned to the interpreter who speaks the language they want to hear.

Health or medical interpreters and translators typically work in healthcare settings and help patients communicate with doctors, nurses, technicians, and other medical staff. Interpreters and translators must have knowledge of medical terminology and of common medical terms in both languages. They may translate research material, regulatory information, pharmaceutical and informational brochures, patient consent documents, website information, and patients’ records from one language into another.

Healthcare or medical interpreters must be sensitive to patients’ personal circumstances, as well as maintain confidentiality and ethical standards. Interpretation may also be provided remotely, either by video relay or over the phone.

Liaison or escort interpreters accompany either U.S. visitors abroad or foreign visitors in the United States who have limited English proficiency. Interpreting in both formal and informal settings, these specialists ensure that the visitors can communicate during their stay. Frequent travel is common for liaison or escort interpreters.

Legal or judicial interpreters and translators typically work in courts and other legal settings. At hearings, arraignments, depositions, and trials, they help people who have limited English proficiency. Accordingly, they must understand legal terminology. Many court interpreters must sometimes read documents aloud in a language other than that in which they were written, a task known as sight translation. Legal or judiciary interpreters and translators must have a strong understanding of legal terminology.

Literary translators convert journal articles, books, poetry, and short stories from one language into another language. They work to keep the tone, style, and meaning of the author’s work. Whenever possible, literary translators work closely with authors to capture the intended meaning, as well as the literary and cultural characteristics, of the original publication.

Localizers adapt text and graphics used in a product or service from one language into another language, a task known as localization. Localization specialists work to make it appear as though the product originated in the country where it will be sold. They must not only know both languages, but also understand the technical information they are working with and the culture of the people who will be using the product or service. Localizers make extensive use of computer and web-based localization tools and generally work in teams.

Localization may include adapting websites, software, marketing materials, user documentation, and various other publications. Usually, these adaptations are related to products and services in information technology, manufacturing and other business sectors.

Sign language interpreters facilitate communication between people who are deaf or hard of hearing and people who can hear. Sign language interpreters must be fluent in English and in American Sign Language (ASL), which combines signing, finger spelling, and specific body language. ASL is a separate language from English and has its own grammar.

Some interpreters specialize in other forms of interpreting for people who are deaf or hard of hearing.

Some people who are deaf or hard of hearing can lip-read English instead of signing in ASL. Interpreters who work with these people do “oral interpretation,” mouthing speech silently and very carefully so that their lips can be read easily. They also may use facial expressions and gestures to help the lip-reader understand.

Other modes of interpreting include cued speech, which uses hand shapes placed near the mouth to give lip-readers more information; signing exact English; and tactile signing, which is interpreting for people who are blind as well as deaf by making hand signs into the deaf and blind person’s hand.

Trilingual interpreters facilitate communication among an English speaker, a speaker of another language, and an ASL user. They must have the versatility, adaptability, and cultural understanding necessary to interpret in all three languages without changing the fundamental meaning of the message.