However, to ensure that there is no confusion, let me lay out my own definition of what plagiarism is. If you use the words of another person, even just one sentence or clause, then you should put those words in quotation marks and give that person credit for their words by providing a citation. If you fail to do so, that is plagiarism. If you use another person's idea, you should give that person credit by providing a citation. Failure to do so is plagiarism. Anything that does not originate within your own mind should be credited to the person where the idea or words did originate. Failure to do so is plagiarism.
Consider this your first warning. Instances of plagiarism that I find will, at a minimum, involve you receiving a zero for the assignment, and at the maximum will involve you failing the course and being reported to the Dean of Students.
Basically, don't plagiarize, and we'll all be a lot happier.
If you have an incredibly good reason for having a late assignment, you must discuss it with me at least 24 hours before the assignment is due. I cannot emphasize this enough. Generally, if you come to me a couple days before something is due, I'll be pretty lenient. If you write me at midnight the night before something is due (it's happened), then you're going to be out of luck. My leniency decreases the closer it gets to when an assignment is due.
Examples of good reasons: