Cool MateEnquiry vs Investigation vs Probe vs Question vs Request
When to use each in English, with meaning, register, and examples.
Enquiry
Top 5,000 (fairly common)B2noun
Investigation
Top 2,000 (common)B2noun
Probe
Top 2,000 (common)C1noun
Question
Top 1,000 (very common)A1noun
Request
Top 1,000 (very common)A2noun
| Enquiry | Investigation | Probe | Question | Request | |
|---|---|---|---|---|---|
| Pronunciation | 🇬🇧 /["/ɪnˈkwaɪəri/"]/🇺🇸 /["/ˈɪnkwəri//ɪnˈkwaɪəri/"]/ | 🇬🇧 /["/ɪnˌvestɪˈɡeɪʃn/"]/🇺🇸 /["/ɪnˌvestɪˈɡeɪʃn/"]/ | 🇬🇧 //prəʊb//🇺🇸 //proʊb// | 🇬🇧 /["/ˈkwestʃən/"]/🇺🇸 /["/ˈkwestʃən/"]/ | 🇬🇧 /["/rɪˈkwest/"]/🇺🇸 /["/rɪˈkwest/"]/ |
| Meaning | A question or a request for information. | Looking into something to find out more about it. | A tool to investigate or explore something deeply. | A sentence or phrase that asks for information. | to ask for something |
| Example | I made an enquiry about the availability of the product. | The police launched an investigation into the missing person's case. | The scientists sent a probe to study the surface of Mars. | The teacher asked a difficult question during the exam. | I would like to make a request for a day off next week. |
| Register | Neutral | Neutral | Neutral | Neutral | Neutral |
| How common | Top 5,000 (fairly common) | Top 2,000 (common) | Top 2,000 (common) | Top 1,000 (very common) | Top 1,000 (very common) |
| CEFR level | B2 | B2 | C1 | A1 | A2 |
| Part of speech | noun | noun | noun | noun | noun |
| Collocations | detailed, thorough, full, carry out, conduct, have, be underway, take place, begin, report, team, process, at an/the enquiry, during an/the enquiry, in an/the enquiry, a steward’s enquiry, the outcome of an enquiry, the result of an enquiry, exhaustive, extensive, thorough, flood, stream, make, pursue, send, desk, office, service, pending enquiry, enquiry about, enquiry as to, direct an enquiry to somebody, careful, systematic, further, encourage, enquiry concerning, enquiry into, an area of enquiry, a board of enquiry, a commission of enquiry | careful, close, detailed, carry out, conduct, pursue, demonstrate something, reveal something, show something, on investigation, under investigation, investigation into, the subject of an investigation, careful, close, detailed, carry out, conduct, pursue, demonstrate something, reveal something, show something, on investigation, under investigation, investigation into, the subject of an investigation | space probe, medical probe, investigative probe, deep probe | awkward, difficult, embarrassing, ask (somebody), have, address, question about, question as to, question concerning to, awkward, difficult, embarrassing, ask (somebody), have, address, question about, question as to, question concerning to, burning, challenging, controversial, bring up, pose, raise, arise, go unanswered, remain unanswered, question about, question for, question of, come into, call into, be open to, beyond question, in question, without question | special, legitimate, reasonable, make, put in, send, at somebody’s request, by request, on request, available on request, available upon request, by popular request, special, legitimate, reasonable, make, put in, send, at somebody’s request, by request, on request, available on request, available upon request, by popular request |
| Antonyms | answer, response | disregard, neglect, overlook | ignore, avoid | answer, solution | refuse, decline |
| Common mistakes | Confused with 'inquiry'; 'enquiry' is often British English., Using 'enquiry' in informal contexts where 'question' is more suitable., Incorrect pluralization; 'enquiries' should not be replaced with 'enquiries'. | Confused with 'invest' which means to put money into something., Using 'investigation' as a verb instead of a noun., Mixing up 'investigation' with 'inspector', which refers to a person. | Confused with 'probe' as a verb instead of a noun., Used too generically; may not be appropriate in informal contexts. | Confusing 'question' with 'query' in formal contexts., Using 'questions' as a singular noun, e.g., 'I have a question' instead of 'I have questions.' | Using 'request' with a different preposition, such as 'request for'., Confusing 'request' with 'require'., Not using it in the correct form, like 'requested' instead of 'requesting'. |
| Usage notes | Use 'enquiry' in formal or business contexts when asking for information. In casual conversations, 'question' may be more common. Avoid using 'enquiry' in very informal settings. | Use 'investigation' in formal contexts, like police work or research. Avoid in casual conversations. | Used in scientific and technical contexts, as well as metaphorically in discussions about examining issues. Not commonly used in casual conversation. | Use 'question' in both formal and informal settings. It's appropriate in classrooms, interviews, and casual conversations. Avoid using in situations where a statement is expected. | Used in polite or formal contexts. It may sound too formal for casual conversations, where simpler words like 'ask' are preferred. |
See it in real clips
Frequently asked questions: Enquiry vs Investigation vs Probe vs Question vs Request
What's the difference between Enquiry, Investigation, Probe, Question, and Request?
Enquiry: A question or a request for information. Investigation: Looking into something to find out more about it. Probe: A tool to investigate or explore something deeply. Question: A sentence or phrase that asks for information. Request: to ask for something
Which is more advanced: Enquiry, Investigation, Probe, Question, and Request?
Probe is the highest level, at C1, on the CEFR scale.
Are Enquiry, Investigation, Probe, Question, and Request the same CEFR level?
Enquiry: B2, Investigation: B2, Probe: C1, Question: A1, Request: A2 on the CEFR scale.
What part of speech are Enquiry, Investigation, Probe, Question, and Request?
Enquiry: noun, Investigation: noun, Probe: noun, Question: noun, Request: noun.
Can you show an example of each?
Enquiry: I made an enquiry about the availability of the product. Investigation: The police launched an investigation into the missing person's case. Probe: The scientists sent a probe to study the surface of Mars. Question: The teacher asked a difficult question during the exam. Request: I would like to make a request for a day off next week.
Can I use Enquiry, Investigation, Probe, Question, and Request interchangeably?
Not always. Enquiry, Investigation, Probe, Question, and Request are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.