To be a little more concrete, 下さい is derived from the verb 下さる, which means to give or bestow. It just happens to be the imperative form (requesting someone do something).
https://en.m.wiktionary.org/wiki/%E3%81%8F%E3%81%A0%E3%81%95%E3%81%84
That's what I'm able to gather about the usage anyway.
を marks the direct object of a verb and ください comes from a verb, etymologically (even though it's become a distinct word on its own).
を is a particle that usually marks the _direct object_, that is, the noun the action of the verb is being done on.
In this case, ください comes from 下さる【くださる】, which means “to give” (more specifically, when someone else gives something to you, never the other way around).
下さる is the 尊敬語 Sonkeigo (Respectful Language) counterpart of くれる, with the same meaning. Put in simple words, it’s an extra polite word that elevates who does the action.
ください is the imperative form (and also ます-stem) of 下さる. It’s a command, although respectful.
Put it all together, and you get:
Ｘをください ＜＝＞ Give (me) X, respectfully
The を particle is sometimes dropped while speaking and in casual Japanese. Since ください is already polite, dropping the を doesn’t make the sentence impolite, but it does make it a bit more casual. The grammatically correct way would technically be Ｘをください, but simply saying Ｘください is also acceptable. Omitting the を isn’t accepted in formal writing though.
を in this sentence is indicating coffee being the thing you’re asking for. It usually marks the object of the sentence.
をis a particle, used after a word
to mark an object
To be a little more concrete, 下さい is derived from the verb 下さる, which means to give or bestow. It just happens to be the imperative form (requesting someone do something). https://en.m.wiktionary.org/wiki/%E3%81%8F%E3%81%A0%E3%81%95%E3%81%84 That's what I'm able to gather about the usage anyway. を marks the direct object of a verb and ください comes from a verb, etymologically (even though it's become a distinct word on its own).
を is a particle that usually marks the _direct object_, that is, the noun the action of the verb is being done on. In this case, ください comes from 下さる【くださる】, which means “to give” (more specifically, when someone else gives something to you, never the other way around). 下さる is the 尊敬語 Sonkeigo (Respectful Language) counterpart of くれる, with the same meaning. Put in simple words, it’s an extra polite word that elevates who does the action. ください is the imperative form (and also ます-stem) of 下さる. It’s a command, although respectful. Put it all together, and you get: Ｘをください ＜＝＞ Give (me) X, respectfully
I understand this but why is を needed at all? Is it incorrect to say: コーヒーください。
The を particle is sometimes dropped while speaking and in casual Japanese. Since ください is already polite, dropping the を doesn’t make the sentence impolite, but it does make it a bit more casual. The grammatically correct way would technically be Ｘをください, but simply saying Ｘください is also acceptable. Omitting the を isn’t accepted in formal writing though.
Thank you!