Imperative

The imperative is a grammatical mood that forms commands or requests, including the giving of prohibition or permission, or any other kind of advice or exhortation. An example of a verb in the imperative mood is be in the English sentence "Please be quiet."

Taking a glance at imperatives

"Are you curious about the meaning of the imperative mood? Then please read this webpage."

The previous sentence is actually in the imperative mood. This is because we directly told you to do something—and that's basically what the imperative mood is. 

One of the main features of the imperative in English is that the subject is usually dropped from the sentence. For example, in the sentence, "Read this webpage," we didn't say "you read." The "you" is implied (similar to the implied actions in finite verbs). This is because the imperative mood almost always consists of a direct communication between one person and another person. 

Using imperative in a sentence

For your reference, here is an example of the imperative being used in a correct way. 

"Please read the instructions for operating the machine; if you don't, then don't blame anyone else if you get hurt." 

In this sentence, both the verbs "read" and "blame" are being used correctly in the imperative. 

Now, here's an example of the incorrect use of the imperative. 

"He doesn't ever arrive late, and this kind of punctuality tended to sometimes unnerve at least some of his friends." 

There is no imperative present here, since there is no command. The beginning of the sentence is a statement of fact, not a request to do something. 

In case you're still a little confused, here are a couple rules you can follow in order to make sure that you are making good use of the imperative. 

1. The imperative is only present when one person is telling another person to do something. There must be some sort of command or request being made for a given action to be performed. In the absence of such a command or request, there can be no command; there could only be a hypothesis or a statement of fact. 
2. Sometimes, it can become hard to tell whether a sentence is in the imperative mood, due to the fact that a command/request can be lightened for the sake of politeness. For example, if someone tells you that "maybe you should study", then this could either be a command or a hypothetical statement, depending on the context (for example, on whether the speaker has authority). 

Derived from social relationships

The imperative mood clearly derives from the nature of certain kinds of social relationship and interactions between human beings. For example, parents tend to speak in the imperative mood to their children ("Eat your spinach"), just as leaders tend to speak in the imperative to their subordinates ("Do your job").

The imperative can thus be conceptualized as a function of social hierarchy and relations of authority and/or respect. The nature of social life is such that at sometimes, some people tell others to not do something. This could be as simple, for example, as your friend telling you to not talk about something. This would be an example of your friend giving you an imperative. 

In general, the imperative is pretty straightforward; but again, the only tricky part, sometimes, is trying to decide whether a given sentence actually is spoken in the imperative or not. This is because relations of authority can be abrasive, and people often try to make polite "suggestions" rather than giving outright commands to others. In such situations, it can become difficult to tell, on strictly grammatical grounds, whether a sentence is in fact in the imperative mood. Some knowledge would be needed about the more general nature of the social relationship that prevails between the speakers.