Social hierarchy: In some cultures, there may be a strong emphasis on social hierarchy, and this can be reflected in the way people speak to each other. Formal commands are often used when speaking to someone who is higher in status, while informal commands are used when speaking to someone who is lower in status or to a close friend or family member.
Politeness: In some cases, formal commands may be used simply as a way to be polite. This is especially common in situations where the speaker does not know the person they are speaking to very well or does not want to appear rude.
Emphasis: In some cases, formal commands may be used to add emphasis to a command. This is often the case when the speaker is trying to make sure that the person they are speaking to understands the importance of the command.
Tone of voice: In some cases, the tone of voice that is used can indicate whether a command is formal or informal. A formal command is typically spoken in a firm and authoritative tone of voice, while an informal command is typically spoken in a more casual and friendly tone of voice.
Grammar: In some cases, there is a grammatical distinction between formal and informal commands. In some languages, for example, the formal command form might have a different verb ending or be used with a different set of pronouns.
It is important to note that the use of formal and informal commands is not always clear-cut. There may be some cases where it is not entirely clear whether a particular command is formal or informal. Additionally, the use of formal and informal commands may vary depending on the region of a country or the particular social context in which the language is being used.