You would be plagiarizing in any of the following three basic instances:

1. If you fail to enclose quoted material within quotation marks.
2. If you do not cite the source of a direct quotation in the text of the paper and/or on the Works Cited or Reference page, or if you do not identify the correct source of a quotation.
3. If you include paraphrased or summarized information (that is not "common knowledge") but do not properly acknowledge its source within parentheses and in the Works Cited list.