My personal philosophy is one in which I feel that learning a language is frequently a cooperative endeavor. On a basic level, this is knowledge that builds bridges and is meant to be shared. We study the words and ideas of other cultures in order to engage in a dialogue with them. At times, students should take the conversation out of the classroom. By sharing their knowledge with others, everyone benefits regardless as to whether or not an individual is studying the language formally.
When students take tests and quizzes and do written assignments such as essays and reports, however, I expect them to present their own ideas on the test and quizzes or acknowledge any help they have received on other assignments from friends, tutors, family, as well as all written and/or electronic sources.
Plagiarism and cheating are intellectual theft. Stealing is a crime. I prosecute for both to the fullest extent of the law (i.e. school/district policy).