Understanding language in society means that one also has to understand the social networks in which language is embedded. A social network is another way of describing a particular speech community in terms of relations between individual members in a community. A network could be loose or tight depending on how members interact with each other.For instance, an office or factory may be considered a tight community because all members interact with each other. A large course with 100+ students would be a looser community because students may only interact with the instructor and maybe 1–2 other students. A multiplex community is one in which members have multiple relationships with each other.[11] For instance, in some neighborhoods, members may live on the same street, work for the same employer and even intermarry.
The looseness or tightness of a social network may affect speech patterns adopted by a speaker. For instance, Sylvie Dubois and Barbara Horvath found that speakers in one Cajun Louisiana community were more likely to pronounce English "th" [θ] as [t] (or [ð] as [d]) if they participated in a relatively dense social network (i.e. had strong local ties and interacted with many other speakers in the community), and less likely if their networks were looser (i.e. fewer local ties).
A social network may apply to the macro level of a country or a city, but also to the inter-personal level of neighborhoods or a single family. Recently, social networks have been formed by the Internet, through chat rooms, MySpace groups, organizations, and online dating services.