One of the differences between American and British English is the usage of the words round and around. Americans use aroundin contexts in which most British speakers prefer round.
The word round has five grammatical functions: noun, verb, adjective, adverb, and preposition.
Round came into the language as a noun meaning “a circular object.” At various times, the “circular object” was a racecourse, a ring, and a coin. In a text from 1325, round is the word used for a diadem encircling the head of a man in a painting. Chaucer used round in the sense of a globe. In Macbeth, Shakespeare used round as a word for a sovereign’s crown.
Around was formed from the noun round by adding the prefix a-, a variation of the prefix on-, creating an adverb that meant “in a circle.”
In some contexts, British speakers use round and around interchangeably; for example, either “He put his arm round her,” or “He put his arm around her.”
Otherwise, according to a note in the British English section of Oxford Dictionaries, there’s a general preference among British speakers to use round for “definite, specific movement,” and around in contexts that are less definite. For example,
American usage sometimes reflects British usage by using round, but around is more common.
Although the Oxford note says that in most contexts, “round is generally regarded as informal or non-standard,” I haven’t found anything in Merriam-Webster or the Chicago Manual of Style to indicate that using round the way the British do is “non-standard” in American usage. It may be old-fashioned, but it is not unknown in American writing:
The usage is still seen in emails and web comments by American speakers:
The strange form ‘round crops up in both British and American contexts, but as round is not a shortening of around, and as there’s no law against the American use of round to mean around, the apostrophe makes no sense in either dialect.