Is Prognosis Singular or Plural?
The short answer is that prognosis is singular. It refers to one medical prediction about the likely course or outcome of a disease. The plural form is prognoses (pronounced prog-NO-seez). This follows the standard rule for Greek-derived nouns ending in -sis, where the -sis changes to -ses in the plural. You would say “The doctor gave a prognosis” for one patient, and “The team reviewed several prognoses” for multiple patients.
Quick Answer
- Singular: prognosis (one prediction)
- Plural: prognoses (multiple predictions)
- Common mistake: Using “prognosises” or “prognosi” — both are incorrect.
- Rule: Words like diagnosis, prognosis, and crisis all follow the same pattern: singular ends in -sis, plural ends in -ses.
Understanding Prognosis in Medical Context
In medical writing and conversation, prognosis is a precise term. It is not the same as a diagnosis. A diagnosis identifies what condition a patient has, while a prognosis predicts how that condition will develop. Because the word is used in serious clinical settings, getting the singular and plural forms right matters for clarity and professionalism.
Formal vs. Informal Tone
In formal medical reports, research papers, or patient notes, you will almost always see the correct singular and plural forms. For example:
- Formal (written): “The prognosis for this patient is guarded.”
- Formal (written): “The prognoses for the three trial groups differed significantly.”
In informal conversation, such as between colleagues or in a quick email, people sometimes drop the word entirely and say “outlook” or “expected outcome.” However, when you do use prognosis or prognoses, using the correct form shows you understand medical terminology.
Email Context
In professional emails, especially those involving patient care or research, precision is key. Consider these examples:
- Correct: “Attached is the prognosis for Mr. Chen.”
- Correct: “We need to compare the prognoses for all patients in the study.”
- Incorrect: “We need to compare the prognosis for all patients.” (This would imply one prediction for multiple patients, which is usually not the case.)
Comparison Table: Prognosis vs. Prognoses
| Feature | Prognosis (Singular) | Prognoses (Plural) |
|---|---|---|
| Number | One | More than one |
| Example context | One patient, one disease, one prediction | Multiple patients, multiple diseases, or multiple predictions |
| Common usage | “The prognosis is good.” | “The prognoses vary by age group.” |
| Verb agreement | Singular verb (e.g., “is,” “was”) | Plural verb (e.g., “are,” “were”) |
| Pronunciation | prog-NO-sis | prog-NO-seez |
Natural Examples
Here are examples that show how prognosis and prognoses appear in real medical writing and conversation.
Singular Examples
- “The oncologist explained the prognosis to the family in clear terms.”
- “A poor prognosis does not mean there is no hope, but it does guide treatment decisions.”
- “What is the prognosis for someone diagnosed at stage one?”
- “Her prognosis improved after the new medication was introduced.”
Plural Examples
- “The study compared the prognoses of patients who received early intervention versus those who did not.”
- “We reviewed the prognoses for all 200 participants before drawing conclusions.”
- “Different cancers have very different prognoses, even at similar stages.”
- “The doctor shared the prognoses for the two groups, and they were not identical.”
Common Mistakes
Even experienced English speakers sometimes make errors with this word. Here are the most frequent mistakes and how to avoid them.
Mistake 1: Using “Prognosises”
Some learners add a regular English plural ending to prognosis, creating prognosises. This is incorrect. The word comes from Greek, and its plural follows the Greek pattern: prognoses.
Incorrect: “The doctors discussed several prognosises.”
Correct: “The doctors discussed several prognoses.”
Mistake 2: Using “Prognosi”
Another error is treating it like an Italian or Latin word and changing the ending to -i. This is not correct for Greek-derived nouns.
Incorrect: “The prognosi were all different.”
Correct: “The prognoses were all different.”
Mistake 3: Using the Singular Form for Multiple Patients
Sometimes people write “the prognosis for the patients” when they mean multiple predictions. If each patient has a separate prognosis, use the plural.
Incorrect: “The prognosis for the patients in the trial was recorded.” (This sounds like one prediction for the whole group.)
Correct: “The prognoses for the patients in the trial were recorded.” (This clearly means each patient had their own prediction.)
Better Alternatives and When to Use Them
While prognosis is the correct medical term, there are times when a simpler word works better, especially in everyday conversation or patient-friendly communication.
When to Use “Prognosis”
- In formal medical reports and research papers.
- When speaking with other healthcare professionals.
- In academic or educational contexts about medicine.
When to Use Alternatives
- Outlook: A good choice for patient conversations. “The outlook is positive.”
- Expected outcome: Useful in plain-language summaries. “The expected outcome varies by case.”
- Prediction: Works in general contexts. “The doctor’s prediction was accurate.”
- Forecast: Less common in medicine but understandable. “The forecast for recovery is good.”
Using these alternatives does not mean prognosis is wrong. It simply gives you flexibility depending on your audience. For example, in an email to a patient’s family, you might write: “The outlook is encouraging” instead of “The prognosis is favorable.” Both are correct, but the first may feel more accessible.
Mini Practice Section
Test your understanding with these four questions. Answers are provided below.
Question 1
Which sentence is correct?
A. The doctor gave a positive prognoses.
B. The doctor gave a positive prognosis.
Question 2
Fill in the blank: “The researchers compared the ______ of patients in different age groups.”
A. prognosis
B. prognoses
Question 3
True or false: “Prognosises” is an acceptable plural form.
Question 4
Which verb form fits? “The prognosis for the new treatment ______ encouraging.”
A. is
B. are
Answers
- B. “Prognosis” is singular, so it matches the singular article “a.”
- B. “Prognoses” is needed because the sentence refers to multiple patients.
- False. The correct plural is “prognoses.”
- A. “Prognosis” is singular, so it takes the singular verb “is.”
Frequently Asked Questions
1. Is “prognosis” ever used as a plural?
No. Prognosis is always singular. If you need a plural, use prognoses. Using prognosis to refer to multiple predictions is grammatically incorrect and can confuse your reader.
2. How do you pronounce “prognoses”?
The plural prognoses is pronounced prog-NO-seez. The last syllable rhymes with “seas” or “please.” The singular prognosis ends with a softer “sis” sound, like “sister” without the “ter.”
3. Can “prognosis” be used outside of medicine?
Yes, but it is rare. In business or economics, you might hear someone say “the prognosis for the market is uncertain.” However, this is less common than using outlook or forecast. In medical contexts, prognosis is the standard term.
4. What is the difference between “diagnosis” and “prognosis”?
A diagnosis identifies a disease or condition. A prognosis predicts its likely course. Both follow the same plural rule: diagnoses and prognoses. For example: “The diagnosis was diabetes, and the prognosis was good with proper management.”
Final Note
Getting prognosis and prognoses right is a small but important detail in medical English. Whether you are writing a patient note, sending an email to a colleague, or studying for an exam, using the correct form shows attention to accuracy. For more help with medical plurals, explore our guides on Common Plural Forms and Plural Spelling Rules. If you have questions, visit our FAQ page or contact us.
