Final answer:
Citing sources is required when using a quotation, summarizing without crediting the source, or omitting quotation marks.
Step-by-step explanation:
Situations that require the inclusion of a citation:
- The author is using a quotation from another person
- The author is summarizing a published author's idea without crediting the source
- The author credits an author's idea in a signal phrase but omits quotation marks
In these situations, it is important to include a citation to give credit to the original source and avoid plagiarism. Citing your sources also helps establish your authority and credibility with readers. Remember to use a signal phrase or quotation marks to introduce the borrowed or quoted material and provide information about the source.