你想要啤酒嗎??

其實兩樣都可以, but用would you like ......會比較有禮貌d.

Would 嘅用法同 will 好似. 好似 could 同 can o甘. Because would 係 will 嘅過去式, 而 could 就係 can 嘅過去式.

用 Would 嘅問題係帶有表示婉轉嘅請求.
用 Would 嘅回答係帶有願意成份.

而 Do 就無左呢 d 成份, 就比較係一個構成疑問句嘅字.

(表示喜歡,意願)願意,要,想
I would like to have a word with you.
我想同你說句話。

would like係較有禮貌既
所以我覺得係Would you like a beer?

Do you want some beer?

你想要啤酒嗎=Do you want a beer?

用do u.....