The plural of “syllabus” can be either “syllabuses” or “syllabi,” and both are considered correct in English usage. However, each carries slightly different connotations depending on the context in which they are used.

1. Syllabuses: This is the Anglicized plural form of the word and is commonly used in everyday English. As the word “syllabus” has been fully integrated into the English language, using “syllabuses” is perfectly acceptable and understood by most speakers. It aligns with the typical pattern of forming plurals in English by simply adding “-es” to the end of the word. This form is safe to use, especially in informal contexts or when communicating with a general audience.
2. Syllabi: This form derives from Latin, where the plural of “syllabus” would indeed be “syllabi.” The use of this foreign plural marks the word as being of Latin origin and is often seen in more formal, academic, or technical contexts. Using “syllabi” can suggest a higher level of education or familiarity with classical languages, as it aligns with the tradition of using Latin plurals for academic and scholarly terms. However, it also can come off as somewhat pretentious if used incorrectly or in the wrong setting.

Contextual Usage:

• In academic or formal contexts, “syllabi” might be preferred because it carries an air of tradition and scholarly sophistication.
• In everyday or informal settings, “syllabuses” is generally more appropriate and understood by a wider audience.

General Recommendation:

When in doubt, especially if you are not familiar with the specific rules of Latin pluralization, it’s safer to use the Anglicized form, “syllabuses.” While using “syllabi” can indicate a certain level of erudition, using it incorrectly can have the opposite effect and give an impression of trying to use language inappropriately.

Additional Considerations:

• Consistency: Whichever form you choose, it’s best to be consistent throughout your writing. Switching between “syllabuses” and “syllabi” in the same document can be confusing.
• Audience: Consider who your audience is. For a general audience, “syllabuses” is usually the better choice. For an academic audience, “syllabi” might be more expected.