- Traditionally, enquire simply meant “ask,” while inquire was used for formal investigations.
- In the UK, the two words are used interchangeably, although inquire is still the more commonly used word for formal or official investigations.
- In the United States, inquire is the strongly preferred spelling in all uses.
For the most part, you can use either enquire or inquire and not make a mistake. These two words, however, have traditionally been used in a slightly different way, at least in the UK, which kind of makes them a pair of commonly confused words.
When to Use Inquire?
Inquire is what you’ll usually see in American English. It means “to ask” or “to investigate”:
In British English, inquire has traditionally been used for formal or official investigations and queries:
Today, the word inquire is also used in British English in the way it’s used in American English, to denote a general query.
When to Use Enquire?
Enquire is mostly used in British English for the general meaning “to ask” or “to investigate”:
While inquire is also often used in the same sense as enquire in British English, it doesn’t usually go the other way around—enquire is rarely used for an official investigation or query.
from Grammarly Blog https://www.grammarly.com/blog/inquire-enquire/