Functional English is usage of the English language required to perform a specific function.
This is typically taught as a foundation subject when a good command of English is required for academic study and career progression.
[1] In some cases, a particular form of technical English, such as Aviation English, may be required for a particular vocation.
Such specialised usage is known and taught as English for Specific Purposes (ESP).
[2] Functional English differs from traditional English studies by emphasizing practical communication skills over literary analysis.