what is the purpose of a comma in a sentence
Comma The comma is used in many contexts and languages, mainly for separating parts of a sentence such as clauses, and items in lists, particularly when there are three or more items listed. The word comma comes from the Greek κόμμα (kómma), which originally meant a cut-off piece; specifically, in grammar, a short clause.[1][2]
Sentence spacing The desired or correct sentence spacing is often debated but many sources now say additional space is not necessary or desirable.[9] From around 1950, single sentence spacing became standard in books, magazines and newspapers,[10] and the majority of style guides that use a Latin-derived alphabet as a language base now prescribe or recommend the use of a single space after the concluding punctuation of a sentence.[11] However, some sources still state that additional spacing is correct or acceptable. The debate continues.[3] Many people prefer double sentence spacing for informal use because that was how they were taught to type.[12] There is a debate on which convention is more readable; the few recent direct studies conducted since 2002 have produced inconclusive results.[13]