Colloquial speech is defined as spoken language used in an informal setting. Colloquial speech frequently ignores formal rules of grammar and pronunciation and is often considered a less educated mode of speech. Colloquialisms are often defined by the instances in which they are considered inappropriate. One example of a common colloquial greeting in North America is "What's up?"
According to the Merriam-Webster online dictionary colloquial speech is any speech that is conversational in nature. Colloquialisms are not considered appropriate in formal communications used in an educational or business style setting. In most formal settings "Whats goin' on y'all?" is too informal. Formal settings require a formal mode of speech that friends or family would consider rude or annoying in an informal setting.
Colloquial speech is generally acceptable for use in informal settings ranging from the home to general social events. Instances where it is appropriate to use colloquialisms differ from one situation to the next. A colloquialism considered inappropriate for use during a religious ceremony may be perfectly acceptable during the social gathering afterwords. The types of colloquialisms considered appropriate for use and the circumstances they are allowed in differ from one region to the next.
Colloquialisms varying widely from one region to the next due to differences in regional speech patterns. Sometimes these differences are created when someone makes a word that catches on with others. How far it spreads depends on how frequently it is used and how many people are exposed to it. Variations in a single colloquialism from one region to the next exist due to corruption over time and the interpretation of local culture. Regional colloquial variations frequently range from changes in spelling or pronunciation to contextual use.
Like most forms of language some colloquialisms remain highly localized while others spread rapidly. Airplanes, television, telephones and the Internet are devices that facilitate communication and therefore the spread of colloquialisms. The spread of a colloquialism is also affected by culture and other barriers to communication. These factors determine where and how a colloquialism spreads and whether it is able to spread at all.