Basically speaking, we have formal and informal style in English, which can be divided into five groups: Frozen, formal, Consultative, Casual and Intimate.

英文的语体基本分为正式体和非正式体，详细点还可划分成演说体、正式体、商议体、随意体和亲昵体五种。

youdao

Instead, some of these children attend what are known as non-formal or informal schools. These are supported by communities, religious groups and other organizations.

相反，其中一些孩子就读于非正式学校。这些学校由社区，宗教团体或其它组织支持。

youdao

Use surveys and focus groups to learn, for example, whether women feel excluded from formal and informal networks.

FORBES: Women Are Asking, "Is The Juggling Act Worth It?"