をください details
Examples
please give me — requesting an object
お母さん、お小遣いちょうだい！
okaasan, okozukai choudai!
Mom, give me some pocket money! casual
すみません、お水をください。
sumimasen, o mizu o kudasai.
Excuse me, some water please. neutral
この切手を五枚ください。
kono kitte o gomai kudasai.
Five of these stamps, please. neutral
Formation
{N}をくださいattaches to noun
Notes
In shops and restaurants を routinely drops (ビールください), and that clipped order is fully polite; adding it back sounds slightly more careful, not more courteous.
Related patterns
Similar
One ください, two complements — Nをください asks to be handed a thing, てください asks for an action; only the noun frame drops its particle in quick orders (コーヒーください), the て never drops.
Lookalikes
Identical in romaji ("o kudasai") and near-identical in speech once を drops — but 電話（を）ください requests the thing/act plainly, while お電話ください is the honorific request frame お+stem+ください.