Final answer:
Code-switching is the co-existence of two different forms of language in society, often referred to as a "high" and "low" or "official" and "common" form.
Step-by-step explanation:
The co-existence of two different forms of language in society, often referred to as a "high" and "low" or "official" and "common" form, is called code-switching.
Code-switching is the practice of alternating between two or more languages or language forms, depending on the context and the interlocutors. It is a common phenomenon in multilingual societies where individuals can switch between different dialects, vernaculars, or languages based on the situation.
For example, someone might code-switch when speaking with their family in a local dialect and then switch to a standard form of language when communicating in a professional or academic setting.