Quick Answer: Prognosis Plural

• Singular: prognosis
• Plural: prognoses
• Common mistake: prognosises, prognosi, prognosisses
• Rule: Words from Greek ending in -sis change to -ses (crisis → crises, diagnosis → diagnoses, prognosis → prognoses).

Why the Plural Is Prognoses

English borrowed prognosis directly from Greek. In Greek, nouns ending in -sis form their plural by changing the ending to -ses. This is the same pattern you see with diagnosis (diagnoses), crisis (crises), thesis (theses), and analysis (analyses). There is no English -s or -es suffix added here; the word itself changes its ending.

Comparison Table: Prognosis vs. Similar Medical Plurals

Natural Examples of Prognosis and Prognoses

Seeing the word used in real contexts helps you remember the correct form. Below are examples for both singular and plural, covering formal medical writing, casual conversation, and email communication.

Singular: Prognosis

• Formal medical report: “The patient’s prognosis remains guarded due to the underlying infection.”
• Doctor to colleague: “Her prognosis is excellent after the successful surgery.”
• Email to a referring physician: “I have attached the latest imaging results and a summary of the prognosis for Mr. Chen.”
• Conversation with a family member: “The doctor said his prognosis is good, but we need to wait a few more days.”

Plural: Prognoses

• Formal medical report: “The prognoses for patients in the early intervention group were significantly better than those in the control group.”
• Doctor to colleague: “We reviewed the prognoses for all five cases, and three are very optimistic.”
• Email to a research team: “Please include the individual prognoses for each participant in the final data set.”
• Conversation: “The team discussed the prognoses for the new treatments, and they all looked promising.”

Common Mistakes with Prognosis Plural

Even experienced medical writers sometimes make errors with this word. Here are the most frequent mistakes and how to avoid them.

Mistake 1: Adding a Regular English Plural

Wrong: “The doctor gave three different prognosises.”
Right: “The doctor gave three different prognoses.”

Because prognosis ends in -s, some people add -es as they would with bus (buses) or class (classes). But prognosis is not a regular English noun; it follows the Greek pattern.

Mistake 2: Dropping the Ending Entirely

Wrong: “We compared the prognosis of both groups.” (when meaning multiple)
Right: “We compared the prognoses of both groups.”

Using the singular form when you mean more than one is a common oversight, especially in spoken language.

Mistake 3: Confusing Prognosis with Diagnosis

Some writers mix the plurals. Remember: diagnosis becomes diagnoses, and prognosis becomes prognoses. They follow the same rule, so if you know one, you know the other.

Better Alternatives and When to Use Them

In some contexts, you might want to rephrase to avoid the plural altogether or to use a simpler term. Here are practical alternatives.

When to Use “Prognoses”

Use prognoses in formal medical writing, research papers, case reports, and any situation where precision matters. It is the standard medical term.

When to Use Alternatives

• “Outcomes” – A good alternative in many contexts. Example: “The outcomes for both groups were similar.” This is common in research and conversation.
• “Predictions” – Useful when you want a less technical tone. Example: “The predictions for recovery varied widely.”
• “Forecasts” – Works in informal settings. Example: “The forecasts for the patients were encouraging.”
• “Expected results” – Clear and simple. Example: “We discussed the expected results for each case.”

In a formal email to a colleague, you might write: “I have attached the prognoses for the three new patients.” In a conversation with a patient’s family, you might say: “The expected outcomes are good.” Choose the level of formality that fits your audience.

Mini Practice: Prognosis Plural

Test your understanding with these four questions. Answers are below.

Question 1

Which sentence uses the correct plural form of prognosis?

A) The study examined the prognosises of fifty patients.
B) The study examined the prognoses of fifty patients.
C) The study examined the prognosis of fifty patients.

Question 2

Fill in the blank: “The team reviewed the ______ for all participants before the meeting.”

A) prognosis
B) prognoses
C) prognosises

Question 3

True or false: “Prognoses” is pronounced the same as “prognosis.”

Question 4

Which word follows the same plural rule as prognosis?

A) Virus
B) Diagnosis
C) Status

Answers

Answer 1: B) The study examined the prognoses of fifty patients.
Answer 2: B) prognoses
Answer 3: False. Prognosis is pronounced prog-NO-sis, and prognoses is prog-NO-seez.
Answer 4: B) Diagnosis (diagnoses). Virus becomes viruses, and status becomes statuses.

FAQ: Prognosis Plural

1. Is “prognoses” the only correct plural of prognosis?

Yes. In standard medical English, prognoses is the only accepted plural form. You may occasionally see prognosis used as a mass noun (e.g., “Prognosis is uncertain”), but when referring to multiple individual predictions, use prognoses.

2. How do you pronounce “prognoses”?

It is pronounced prog-NO-seez. The first syllable rhymes with “dog,” the second syllable is stressed like “no,” and the final syllable sounds like “seas.” Do not pronounce it like “prog-NO-sis” (that is the singular).

3. Can I use “prognosis” for multiple patients in informal writing?

In very informal conversation, some people use the singular form even when referring to multiple cases. For example: “What are the prognosis for those patients?” However, this is grammatically incorrect. In any kind of writing—email, report, or study—use prognoses for clarity and correctness.

4. What is the difference between “prognosis” and “diagnosis” in plural form?

Both follow the same Greek rule. Diagnosis becomes diagnoses, and prognosis becomes prognoses. The difference is meaning: a diagnosis identifies a condition, while a prognosis predicts its likely course. In plural, you might say: “The diagnoses were confirmed, and the prognoses were updated.”

Final Note on Using Prognosis Plural

Mastering the plural of prognosis is a small but important step in writing clear medical English. Remember the -sis to -ses rule, practice with real examples, and check your work for the common mistakes listed above. Whether you are writing a formal case study, sending an email to a colleague, or explaining a situation to a patient’s family, using the correct form shows attention to detail and professional care.

For more help with similar medical plurals, visit our Plural Spelling Rules section. You can also explore Common Plural Forms for other frequently confused words, or check Confusing Plurals for terms that often trip up writers. If you have questions about this guide, see our FAQ or contact us.