What is the imperative used for?

The imperative mood is used to tell somebody what to do. This includes the following:

• Warnings (e.g., “Do not enter”)
• Instructions or directions (e.g., “Choose the best answer” or “Turn left here”)
• Advice (e.g., “Wear the black shoes instead of the brown ones”)
• Commands (e.g., “Halt!”)
• Requests (e.g., “Please save me a seat”)