Translation:The white blouse, please.
Arguably, "May I have a white blouse, please" should be acceptable here, but it seems a level or two of politeness above that of the Japanese sentence.
I'm a native English speaker, not native Japanese, but I think your suggested sentence would translate more like 「白いブラウスをいただけますでしょうか」but that's getting into keigo territory shudder
That's what I thought when I first encountered it too. But just because it "sounds" wrong to us who, I assume, have an incomplete understanding of keigo (no offense), doesn't mean it is wrong.
So I did some research. I found this example on Tae Kim's Guide to Learning Japanese (example 4: http://www.guidetojapanese.org/certainty.html#part3) where he states "If you want to sound really, really polite, you can even add 「～でしょうか」 to the end of a 「～ます」 ending."
However, when I looked it up in Japanese, it turns out that it's a mistake that even native speakers commonly make, called 二重敬語. According to the authors here (https://docoic.com/6635 and https://mayonez.jp/topic/5158), it's incorrect because 「ます」 is a form of 丁寧語 or polite language, and so is 「でしょうか」 and that's why you can't have them together.
From the way the articles are written, I would guess it's about as ubiquitous as English speakers mistakenly using "good" when they technically should use "well". Native speakers will understand what you mean, and most probably wouldn't even notice anything was wrong.
I believe that is correct. However, English speakers would never refer to it as a type of blouse- a blouse only refers to a loose-fitting shirt, usually a women’s shirt, and often made of a soft, light material. A lab coat we would consider a type of coat, but not a kind of blouse.
I typed "a white blouse please" and it was correct, I'm glad Duolingo accepts this because it's the better way of learning Japanese when learning from English because it helps to understand more quickly how to form sentences. In contrast to english, the words "Give me" are not needed to understand that the person is asking to be given a white blouse. Usually when ください Kudasai is used, it implies that the person is asking for something, and as far as I know there is almost no way to ask for something without adding the word for 'Please,' which sort of forces people to speak respectfully and less awkwardly demanding.
I think that ください can mean either:
"Please give me (something)"
"Please do (something) for me."
Using please and give me in the same sentence really grates me. I'm assuming this is American phrasing because in the UK telling someone, especially in a store, to give you something is a very rude way of phrasing it and then adding please to the sentence is in stark contrast to that. The sentence just seems so unnatural in a shopping situation in my opinion. May I... or could I... or I'd like... would be so much more accurate a translation I think.
How about "A white blouse, please"?
How about if you were translating into Japanese:
A: "I'll make him wear a white blouse or a smelly potato sack. You choose."
B: "The white blouse, please."
Would you use this sentence if you were B?
Weird example, I know. But my point is when it comes to translating, there is never only one correct answer, especially when you're dealing with Japanese.