The Commonwealth of Pennsylvania enacted legislation in 1990 requiring that every member of an institution of higher learning who teaches undergraduates be tested and certified as fluent in English. At Penn, the English Language Programs (ELP) is responsible for testing and certifying all teaching assistants who use English as a second language (International Teaching Assistants or ITAs).
Prospective ITAs whose first language is not English may demonstrate fluency by receiving a rating of Superior on an ACTFL Oral Proficiency Interview (OPI) or a score of 27 or higher on the Speaking component of the iBT TOEFL. Prospective ITAs who have not taken the TOEFL or an OPI must take the SPEAK test (an institutional version of the TSE). A score above 55 permits automatic certification as fluent in English. Prospective ITAs receiving less than 45 on the TSE or SPEAK, will be counseled to take some language training before trying again. Students who receive scores on the SPEAK of between 45 and 55 inclusive may be certified for classroom instruction by passing the Interactive Performance Test (IPT) administered by the English Language Programs. The IPT consists of a ten minute lecture with a question and answer component on a topic in the candidate's academic discipline. Prospective ITAs who pass this test are certified as fluent in English. Read more about certification here. 
For a schedule of test dates and instructions on how to sign up, either click here  or click on "Test Dates" at the top of this page.
The ELP organizes a seven-week language training program during the summer on behalf of Penn's School of Arts & Sciences (SAS). This program is open to prospective ITAs from all schools at Penn.