When to use these plain Te-Forms?

Question

I've studied the use of a polite(?) te-form conjugation that is used to enumerate actions or for a request (adding ください). Examples would be 聞いて, 死んで.

But what about non-polite(?) te-form conjugations? 聞け, 死ね, when do you use them? They rather seem imperative, as if the speaker were giving an order with an angry tone, but I believe that's actually the case of the 〜なさい suffix.

Answer 1

Let's talk about the imperative in Japanese: an imperative is a way to give orders and/or commands. However, the form of these utterances decides whether they are humble requests to barked orders.

You can find a quite complete reference here

In general you can use a number of forms:

• ます-stem+なさい: this is a polite yet firm request. It is often used to soften orders, between parents and child or boss/employee.

  よく聞｛き｝きなさい！

• て-form+ください or noun+ください: This also a polite way of expressing a request, think of "Please do this". This is widely used, I hear it all the time in classrooms:

  座｛すわ｝ってください！

• The imperative form that is made from either turning the last syllable of a godan verb to the corresponding e pair or by adding ろ to the stem of a ichidan verb. This one is used for strong orders, such as those you give to your dog:

  走｛はし｝れ！ しっかりしろ！

There are other variations, but these are the main imperative forms. Note that the て-form is one imperative form among many others. Usage of those forms depends a lot on the context, mainly the current situation and relationship between the speakers.

An interesting example is 頑張｛がんば｝る, to do one's best, to strive for perfection.

• 頑張りなさい would typically be used by soccer moms encouraging their children.
• 頑張ってください　would be used to encourage a co-worker.
• 頑張って　may be used by friends encouraging you
• 頑張れ　(often written ガンバレ) will be used by sports fan cheering on their favorite team/player.

Unfortunately there is no set rule, so it will take some time to recognize in which situation which form of imperative is to be used.

Answer 2

Choco's right but being pedantic ;)

~て form is often used as a casual direct request/command. ドア開けて！早く飲んで！ Adding くれ！makes it very powerful, impatient, angry, desperate or comic.

~なさい is more how you would politely but strongly address/command/request a child or 'lower' person. You could also see it as one step down in formality from ください。

Like many things, tone, delivery and situation impart a lot of nuance and variety of application.