Different people speak with grammar that differs from that of other people. For example, people who use the dialects called General American English and BBC English might say, "I didn't do anything", while someone who speaks what is called African American Vernacular English or AAVE might say, "I didn't do nothing". London working class version: "I ain't done nuffink!" These are called "double negatives", and are found almost entirely in spoken English, and seldom written.