grammar - What's the difference between なさい and てください / でくださ い?

What is the practical difference between なさい and ください? Is it only different in politeness or does it have a different meaning and application?

Also is なさい used the same way as ください? -te form plus the なさい?

Now there's this sentence I'm trying to come up with, could you help me? Is it right, does it sound natural? What could I improve on that? (I just making these sentence to exercise my grammar)

俺は日本語をちょっと話せますが、のみ簡単の物を話せますのですよ。

In case it is not clear, my intention was something like:

I can talk a bit o Japanese but I can only talk simple stuff.

Answer

Grammatically speaking:

• 「continuative form (連用形) + なさい」 is for telling / ordering someone to do something. なさい is the honorific form of the imperative "しろ (or せよ)". (In other words, なさい is the imperative form of なさる, which is the honorific verb of する.)　


• 「te-form + ください」 is for asking someone to do something. It's the honorific form of 「te-form + くれ」. (くれ is the imperative form of くれる, "to give (me/us)". In other words, ください is the imperative form of くださる, which is the honorific verb of くれる.)

Examples:

見ろ。-- ordering "Look." -- casual form
見なさい。-- ordering "Look." -- polite form

見てくれ。-- asking "(Please) look." -- casual form
見てください。-- asking "Please look." -- polite form

Practically:

• しろ、見ろ etc. are pretty strong, often masculine, and sound a bit rough.


• ～なさい sounds a bit softer than しろ、見ろ etc. but this would make you sound like a school teacher or a mother talking to children. Usually used by someone older/superior towards someone younger/inferior. (And I think it's also often said by police officers...)


• ～てくれ sounds masculine and informal. Instead of しろ or ～てくれ, 「～て。」 is commonly used in daily conversation, especially by female speakers. Eg 見て。助けて。教えて。 You can also say 「～てくれる？」「～てくれない？」("Can you~~?") to sound softer.


• ～てください is politer than the others. If you want to sound even politer and formal, you could use 「～てくださいますか」「～てくださいませんか」("Could you please~~?") etc.

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「俺は日本語をちょっと話せますが、のみ簡単の物を話せますのですよ」
"I can talk a bit of Japanese but I can only talk simple stuff."

• ～を話せる is acceptable but ～が話せる would be more natural. (since 話せる is a potential verb)


• 簡単 is a na-adjective. 簡単の → 簡単な


• 簡単なもの → 簡単なこと (Use もの for physical things, こと for abstract things)


• Place のみ / だけ after 簡単なこと. (eg "only coffee" 「コーヒーだけ / コーヒーのみ」)



• You don't need two polite markers in one verb phrase (×ます～です). 話せますのですよ → 話せるのですよ, 話せるんですよ or 話せますよ


• しか話せない would be more natural than だけが話せる. (しか～ない ≂ only)

俺/僕は日本語がちょっと話せますが、簡単なことしか話せないのですよ。/ 話せないんですよ。

Keep up! :)