相同屬性物的推理問題

可以 a coffee, an orange juice, a tea, a beer
嚴格來說,不可以 a water

coffee, tea, juice, beer 可以是 uncountable noun 或者 countable noun
但是 water 在字典沒有被列為 countable noun
(Oxford, Cambridge, Longman, Merriam-Webster)

在餐廳 order 時, 叫 a jug of water, a bottle of water, two glasses of water
在工作時, 可以說 a molecule of water, two drops of water, two flasks of water, three buckets of water, two pails of water, a tank of water …etc
不知道是否 water 在餐廳, 工作場所, 可以 refer to 不同 容量, 所以要列明 jug, glass, bottle, flask, bucket, pail, tank …etc

如果地區接受 a water, one water, two waters, three waters. Plural 時 water加 -s, 變 waters, 我覺怪怪地, 因為 waters 在英語解 “海域”

以上純粹地是我個人猜測, maybe 新一代青年已經使用 a water, I am behind time!

Yes, you can have a water when you are thirsty.