Questionnaire is the correct spelling ✅ in standard English. Questionaire is the incorrect spelling ❌ and is treated as a misspelling in edited writing.
A questionnaire is a set of questions used to collect information, often for surveys, research, or forms. ✅Source
- Part of speech: Noun
- Core idea: Questions + responses
- Typical setting: surveys, research, feedback
Meaning Of Questionnaire
Questionnaire refers to a written list of questions designed to gather answers in a consistent way. In everyday terms, it’s a structured set of prompts that helps people collect the same kind of information from multiple respondents.
Pronunciation is a big clue to the spelling: many dictionaries show it as /ˌkwes.tʃəˈneər/, which matches the -naire ending you see in questionnaire. ✅Source
Core point A questionnaire is the question set itself. A survey is often the whole activity (designing questions, collecting answers, analyzing results).
Why The Spelling Trips People Up
The mix-up usually happens because questionnaire is borrowed from French and keeps a French-looking ending. That ending is -naire, not -aire. English has plenty of common words ending in -aire (so your brain tries to “fix” it), and questionaire feels familiar even though it’s not standard.
The -naire Ending
In print dictionaries, the spelling questionnaire is treated as the established form, and it’s commonly traced to French usage in the late 19th century. ✅Source
That extra n isn’t decorative. It’s part of the fixed sequence in questionnaire, and it’s one reason the typo questionaire stands out to spell-checkers and editors.
Why “Questionaire” Looks Tempting
The letter pattern in questionaire resembles lots of everyday spellings where -aire is common. So it can feel “right” at a glance, especially in fast typing. Still, major dictionaries and published style writing favor questionnaire as the standard.
Where The Word Is Used
You’ll see questionnaire in places that need consistent answers. The word signals a set of questions meant to be answered in a fairly standardized way, even when the questions themselves are short or long.
Common Settings
- Academic research and social science data collection
- Market research and customer feedback
- HR forms, onboarding, and employee surveys
- Product satisfaction and service evaluation
Typical Wording Around It
- complete a questionnaire
- fill out a questionnaire
- send a questionnaire to participants
- responses from the questionnaire
Dictionaries often show “fill out a questionnaire” as a standard usage pattern. ✅Source
Spelling Status In One Glance
| Form | Status | What It Means | Where It Usually Appears |
|---|---|---|---|
| questionnaire | ✅ Correct | A set of questions used to collect information | Forms, research, surveys, documentation |
| questionaire | ❌ Wrong | Intended to mean questionnaire, but treated as a misspelling | Typos in drafts, informal notes, unedited text |
Examples That Show The Difference
These examples show how questionnaire naturally fits in real sentences. The wrong form questionaire is included only to show the spelling error, not as an accepted variant.
- ✅ Correct Questionnaire
- “Please complete the questionnaire before the meeting so we can review the responses.”
- ✅ Correct Questionnaires (Plural)
- “The team compared several questionnaires to keep the questions consistent across groups.”
- ❌ Wrong Questionaire
- “Please complete the questionaire …” This is treated as a misspelling in standard English.
Notice the ending: -naire. When you see questionnaire in polished documents, that spelling choice is deliberate, and questionaire is typically corrected during editing.
Related Words You Might See
In the same neighborhood as questionnaire, you’ll often run into words like survey, form, and assessment. They overlap, but they’re not always interchangeable in formal writing.
Questionnaire vs Survey
A questionnaire is the question set. A survey can mean the questionnaire, the distribution, and the analysis together. In plain usage, people may say “survey” when they really mean “questionnaire,” but many writers keep the distinction for clarity.
You might also see questionary listed as a word meaning questionnaire, but it’s far less common in everyday English. ✅Source
Common Formatting Choices
Questionnaire is usually written in lowercase as a common noun. It becomes capitalized mainly in titles, headings, or when it’s part of a named document (for example, a specific Questionnaire title inside a report).
The plural is questionnaires, keeping the same -naire sequence. That spelling stays stable whether the questionnaire is short, long, printed, or online.
Common Misspelling Patterns
- questionaire (missing the second n; the most common typo)
- questionnare (dropped an i; looks close but still wrong)
- questionnair (missing the final e; another frequent slip)
FAQ
Is “questionaire” ever correct?
In standard English, questionnaire is the accepted spelling, while questionaire is treated as a misspelling. You might see it in unedited drafts, but it isn’t considered a correct variant.
Why does “questionnaire” have -naire?
Questionnaire is a borrowing with a French-style ending. That fixed letter pattern is why the double n appears and why questionaire looks off in edited writing.
How do you pronounce “questionnaire”?
Many dictionaries show a pronunciation like /ˌkwes.tʃəˈneər/. It lines up with the -naire ending you see in the correct spelling.
What’s the plural of “questionnaire”?
The plural is questionnaires. The ending stays -naire, and you simply add -s like a regular English plural.
Is a questionnaire the same as a survey?
They’re related, but not always identical. A questionnaire is the question set, while a survey can mean the questionnaire plus the collection and analysis of answers.
Is “questionary” a real word?
Yes, questionary exists and can mean questionnaire, but it’s much less common in everyday English. Most modern writing sticks with questionnaire.