enquire vs inquire
Often debated amongst scholars, the Macquarie dictionary explains the two thus:
“The forms are interchangeable. Some organisations, such as newspapers, tend to standardise on the in- form, but there are also those who make a distinction between, for example, an official inquiry and an informal enquiry.”
In British English people sometimes distinguish between enquiry and inquiry, using enquiry for the general meaning of ‘a request for information’ and inquiry for the more particular meaning of ‘official investigation’.