A reader wants to know how between and in between differ in usage:
Please explain the usage of the term “in between.” It’s been many years since I heard anyone say this. I always thought it was unnecessary to combine the words “in” and “between”. What’s the difference if you say that one thing is between another thing as opposed to saying that it’s “in between”?
When between functions as a preposition, placing in before it is nonstandard usage. The following headlines, for example, are incorrect:
Incorrect: Woman dies walking in between subway cars
Correct : Woman dies walking between subway cars
Incorrect: You don’t need to enter spaces in-between the numbers/letters.
Correct : You don’t need to enter spaces between the numbers/letters.
Incorrect: How Many Hurdles are In Between a Thief and Your Phone Data?
Correct : How Many Hurdles are Between a Thief and Your Phone Data?
The addition of in is acceptable when the phrase “in between” functions as a noun or an adjective.
1. In-between as noun
Josie feels like an in-between, trapped between her family’s Italian culture and the Australian culture of her peers. (noun meaning, “a person who doesn’t belong in either of two groups”)
Many times, parents feel like the only choice is to have [the baby] fall asleep in your arms or cry it out, but there really is an in-between. (noun meaning, “an alternative that lies between two extremes”)
2. In-between as adjective
An “in-between hop” is a baseball term that indicates a bounced baseball that reaches an infielder at the midpoint of its upward bounce. (adjective describing hop)
College students on holiday face an in-between world. (adjective describing world)
Bottom line: When using between as a preposition, don’t preface it with in.