Learn Hardcore Chinese: nǐ kěyǐ gěi wǒ yìdiǎnr shuǐ ma?

Here 给 (gěi) is the main verb “to give.” The structure is: 你 + 可以 + 给 + 我 + 一点儿 + 水 + 吗 (“Can you give me a little water?”). When 给 is a coverb/preposition, it means “for/to,” as in 给他打电话 (“call him”).

Is this sentence polite and natural? Should I add 请?

Yes, 你可以给我一点儿水吗？ is already polite and natural because 可以…吗 asks for permission. For extra politeness: 请问，您能给我一点儿水吗？ or 麻烦你/您，给我一杯水可以吗？ Use 请给我一杯水 in service contexts; it can sound formal if used with friends.

What’s the difference between 可以 and 能 here?

可以 focuses on permission/possibility (“is it okay”), while 能 focuses on ability/circumstance (“are you able”). In requests, both are fine; 可以 can feel slightly more courteous. A-not-A forms: 可不可以… and 能不能….

Do I need 吗, or can I just use rising intonation?

Use 吗 for a clear, neutral yes–no question. In casual speech some people drop 吗 and use rising intonation, but in standard/written Chinese keep 吗. Alternative: 可不可以/能不能给我一点儿水？

How is 吗 different from 呢 and 吧?

吗 makes yes–no questions. 呢 continues a topic or asks “how about…?”—not used here. 吧 softens a suggestion/imperative: 给我一点儿水吧 (“How about giving me some water?”), which is a soft command rather than a question.

Why use 一点儿 with 水? Could I say 一些水?

一点儿水 = “a little water,” emphasizing small amount; it’s very idiomatic with liquids. 一些水 (“some water”) is grammatical but sounds more general or a bit larger in amount; it’s less common in a quick request.

What’s the difference among 一点儿, 一点, and 点儿?

Meaning is the same here. In the north you’ll hear 一点儿/点儿 (with -r). In the south/Taiwan, people say 一点/点 (no -r). 点儿/点 is very colloquial; 一点儿/一点 is slightly more explicit.

Where does 一点儿 go? Can I say 水一点儿?

Quantity comes before the noun: 给我一点儿水. 水一点儿 is not correct in this noun phrase. After adjectives/verbs it’s different (e.g., 慢一点儿 “a bit slower”).

Do I need a measure word for 水?

Not when you use 一点儿—it already quantifies the noun. For specifics, use classifiers: 一杯水 (a glass), 一瓶水 (a bottle), 一口水 (a sip), 一点儿温水 (a little warm water).

Is 给我水 okay, or do I need 一点儿?

给我水 is grammatical but blunt. Adding a quantity or a softener is more natural/polite: 可以给我一点儿水吗？/ 给我一杯水，可以吗？

Can I drop 你?

Yes. 可以给我一点儿水吗？ is common when context makes the addressee obvious. You can also say 给我一点儿水，可以吗？ to make it sound even softer.

When should I use 您 instead of 你?

Use 您 with elders, customers, or strangers to be respectful: 您可以给我一点儿水吗？ Adding 请问/麻烦您 makes it extra polite.

How do tones change here? There are many third tones.

Apply third-tone sandhi: a third tone becomes a rising tone before another third tone. A natural reading is roughly: ní kéyǐ gěi wǒ yìdiǎnr shuǐ ma. Also, 一 becomes fourth tone (yì) before the third-tone 点. 吗 is neutral tone.

How do I pronounce 儿 in 一点儿? What if I don’t use 儿化?

With 儿化 (northern), 一点儿 merges to one r-colored syllable: [yì-diǎnr]. Without 儿化 (southern/Taiwan), say 一点 [yì-diǎn]. Both are fine.

Can I use 把 here?

Use 把 only when the water is specific/definite: 可以把水给我吗？ (“the water”). For an indefinite amount (“some water”), don’t use 把; say 给我一点儿水.

Where should 请 go?

Put 请 at the start or before the verb phrase: 请给我一杯水。 Avoid 你可以请给我…吗, which is awkward. Very natural softeners: 请问…, 麻烦你/您….

What are other natural ways to ask for water?

能不能给我点儿水？
可以给我一杯水吗？
麻烦你给我一杯温水。
给我倒点儿水吧。
我可以要一杯水吗？
可以给我一点儿水喝吗？ (explicit “to drink”)

Can 给 also mean “for/to” instead of “give”?

Yes. As a coverb, 给 means “for/to”: 给我打电话 (“call me”), 给他买水 (“buy water for him”). In your sentence it’s the main verb “give.”