Learning how to cite sources is one of the first skills you need for any college essay, research paper, or report. This beginner guide explains why citations matter and walks you through clear, correct examples in two of the most common styles, APA 7th edition and MLA 9th edition.
What does it mean to cite a source?
To cite a source is to tell your reader exactly where a piece of information, idea, or quotation came from. Every time you use someone else’s work, you give credit twice:
- With a short in-text citation inside your sentence or in parentheses.
- With a full reference entry in a list at the end of your paper.
The two parts work together. The short in-text note points the reader to the matching full entry, where they can find the complete details and locate the original source. If you want a deeper definition, see our explainer on what a citation is.
Why citing sources matters
Citations are not just a formality. They serve real purposes:
- They give credit. Using another person’s words or ideas without credit is plagiarism, even when it is accidental.
- They build trust. Readers can check your evidence and see that your claims are supported.
- They help your reader. A clear reference lets anyone find and read the original source.
Citing carefully is the single best way to avoid plagiarism and keep your work honest.
What information you need before you start
Before you can cite anything, collect the basic facts about the source. For most written sources you will need:
- Author name or names
- Year (and full date for some source types)
- Title of the work
- Where it was published (publisher, journal, or website)
- A locator such as page numbers, a URL, or a DOI
Write these details down as you research. It is much faster to gather them once than to hunt for them again the night before a deadline.
How to cite sources in APA style (7th edition)
APA style is used mostly in psychology, education, nursing, and the social sciences. It uses an author and date system. The in-text citation gives the author’s last name and the year, and the full entry appears on a page titled References. For a complete walkthrough, read our APA format guide.
A book in APA
Smith, J. (2020). Writing for beginners. Oxford University Press.
In-text: (Smith, 2020).
Notice the order: author surname, initial, year in parentheses, the book title in italics with only the first word capitalized, then the publisher. There is no longer a publisher location in APA 7th edition. See more in our guide on how to cite a book.
A journal article in APA
Smith, J., & Brown, A. (2021). Reading habits in young adults. Journal of Learning Studies, 12(3), 45–60. https://doi.org/10.1000/example
In-text: (Smith & Brown, 2021).
The article title is in plain text, the journal name and volume number are in italics, the issue number is in parentheses (not italic), and the page range follows. Use an ampersand (&) between authors in APA, both in the reference and in parenthetical in-text citations.
A website page in APA
Smith, J. (2022, March 15). How to study effectively. Study Tips Online. https://www.example.com/study-tips
In-text: (Smith, 2022).
For a web page, include the full date if it is available and the name of the site. Our page on how to cite a website covers tricky cases such as missing authors or dates.
How to cite sources in MLA style (9th edition)
MLA style is common in English, literature, and the humanities. It uses an author and page system. The in-text citation gives the author’s last name and a page number with no comma between them, and the full entry appears on a page titled Works Cited. Our MLA format guide explains the rules in full.
A book in MLA
Smith, John. Writing for Beginners. Oxford University Press, 2020.
In-text: (Smith 24).
In MLA the author’s full first name is spelled out, the title uses headline capitalization, and the year comes at the end. Note that MLA does not put a comma or “p.” before the page number in the in-text citation.
A journal article in MLA
Smith, John, and Anna Brown. “Reading Habits in Young Adults.” Journal of Learning Studies, vol. 12, no. 3, 2021, pp. 45–60.
In-text: (Smith and Brown 52).
The article title goes in quotation marks, the journal name is in italics, and MLA spells out “vol.”, “no.”, and “pp.” Use the word “and” between authors in MLA, not an ampersand.
A website page in MLA
Smith, John. “How to Study Effectively.” Study Tips Online, 15 Mar. 2022, www.example.com/study-tips.
In-text: (Smith).
When an online source has no page numbers, the MLA in-text citation uses just the author’s name. The URL appears in the Works Cited entry without “https://”.
In-text citations: the two formats
Both APA and MLA let you cite in two ways. In a parenthetical citation, all the details go in parentheses. In a narrative citation, the author’s name appears in your sentence and only the rest goes in parentheses.
- APA parenthetical: One study found a clear pattern (Smith, 2020).
- APA narrative: Smith (2020) found a clear pattern.
- MLA parenthetical: One study found a clear pattern (Smith 24).
- MLA narrative: Smith found a clear pattern (24).
For more detail, see our guides to in-text citations and the difference between parenthetical and narrative citations.
A simple step-by-step method
Whatever style you use, the same routine keeps your citing accurate:
- Identify the source type (book, article, website, video).
- Collect the details listed earlier in this guide.
- Pick your style based on your instructor’s requirements.
- Build the reference entry using the correct order and punctuation.
- Add the matching in-text citation wherever you use the source.
- Check the list for alphabetical order and consistent formatting.
To save time and reduce errors, you can build entries with our free citation generator, then switch between the APA citation generator and the MLA citation generator as your assignment requires. Always proofread the output against this guide, because no tool is perfect.
Common mistakes to avoid
- Mixing styles. Choose one style and use it consistently throughout the paper.
- Forgetting the in-text citation. A reference list entry alone is not enough; every source needs a matching in-text note.
- Wrong punctuation. Ampersand versus “and”, commas, and italics all differ by style.
- Citing a quote but not a paraphrase. Paraphrased ideas still need a citation.
If your assignment uses a different style, we also cover Chicago style and Harvard referencing.
Frequently asked questions
What is the difference between an in-text citation and a reference?
An in-text citation is a short note inside your text that points to a source, such as (Smith, 2020) in APA or (Smith 24) in MLA. A reference, also called a Works Cited entry in MLA, is the full description of that source in a list at the end of your paper. You need both, and they must match.
Do I need to cite a source if I put the idea in my own words?
Yes. Paraphrasing means restating someone else’s idea in your own words, but the idea is still theirs, so it must be cited. You only skip a citation for common knowledge, such as widely known facts that appear in many sources without dispute.
Which citation style should I use?
Use the style your instructor or department requires. As a general guide, APA is common in the social sciences and health fields, while MLA is common in English and the humanities. If you are unsure, ask your instructor or check the assignment instructions before you begin.
Can a citation generator do all the work for me?
A citation generator speeds up the process and handles most formatting, but it cannot guarantee perfect results from imperfect input. Always check author names, capitalization, italics, and punctuation against a trusted guide like this one before you submit.