You should include a citation if you:
1. Use a direct quote
2. Summarize an outside source
3. Paraphrase an idea, quote, or passage from someone else
If you are unsure about whether you need to cite, go ahead and do it. Better safe than sorry when it comes to avoiding plagiarism.
For MLA citations, please consult the MLA Handbook in our library catalog, and we recommend the Seneca Libraries online guide and Purdue OWL online guide to learn how to format and write citations in MLA Style.
You can also access tutorial videos from Hoonuit. Log in with your Guilford credentials and search for the course MLA (8th Ed.) Research Paper Basics.
Among these tutorial videos, you will find examples of how to properly cite some of the most common source types, such as books and journal articles.