In the US, inquiry and enquiry are interchangeable, but be aware that many will consider enquiry to be a spelling mistake of inquiry.
In the UK, inquiry and enquiry are interchangeable. However, it is becoming preferable to use inquiry to denote an investigation and enquiry to denote a question.
Enquiry and InquiryThe nouns enquiry and inquiry can mean question, inquest, or investigation. They can be used interchangeably. However, in the US, inquiry is more widely used than enquiry (to the extent that many will consider enquiry a spelling mistake of inquiry).
(NB: The words enquiry and inquiry also have associated verbs (to enquire and to inquire). The guidance on this page relates to the verbs as well as the nouns.)
There Is a Distinction Developing in the UKIn the UK, a distinction between enquiry and inquiry is developing. The word inquiry is being used in relation to a formal inquest (i.e., an investigation), while enquiry is being used to denote the act of questioning. However, there is still considerable leniency on this distinction.
Examples with Inquiry and EnquiryThe examples below align with the convention developing in the UK:
- I would like to enquire about the toilet facilities in the hotel. (Here, to enquire means to ask.)
- The judge has suspended the inquiry into the police shooting of the escaped mental patient. (Here, inquiry means inquest or investigation.)