All sponsors of J Exchange Visitors must retain "evidence" of "objective measures" of a prospective Exchange Visitor’s English proficiency before a DS-2019 can be issued.
As per the Department of State, a prospective visitor should have "sufficient proficiency in the English language as determined by an objective measurement of English language proficiency, successfully to participate in his or her program and to function on a day-to-day basis."
This "objective measure" can take the following forms:
Exemptions are granted to applicants who have earned a US bachelor’s, master’s, or doctoral degree from a college or university accredited by a regional accrediting association in the United States, or the international equivalent degree from a university of recognized standing in a country in which all instruction is provided in English. Therefore, applicants with degrees from the US, Australia, Canada (except Quebec), New Zealand, Singapore, Ireland and the United Kingdom (England, Scotland, Northern Ireland, Wales) are exempt from the English Proficiency requirement.
J Students have already submitted an objective measurement of English proficiency in the form of a recognized English test required of all those admitted to Stanford’s degree seeking programs.