That is actually an interesting question. Having been in both India and America, I have observed that in America, milk is considered appealing when it is cold: "I came home and drank a glass of soothing, cold milk." On the other hand, in India, milk is considered ridiculous to drink when it is cold, and is always heated. "I came home and drank a glass of soothing, warm milk."
I understand. I was talking with another guy in another thread and was wondering if this shortcut was based upon slang and that if one does use "האם" how unusual would it be for a native to hear it. Would it be more comfortable in a formal setting and then not used among friends and family?
Usually in formal speaking you would use "האם", and in day-to-day you wouldn't. Though I'm pretty sure every Hebrew speaker would understand if you'll use "האם". It might be a little unusual to hear in informal setting, almost like an English speaker using "whom" (though not as unusual) hope that clarifies some stuff :)
Weirdly enough, I entered "the milk is hot?" and it marked me as wrong and then suggested "the milk's hot?" as a correct alternative. The alternative suggestion is actually somewhat correct English, even if it sounds funny, but I do find it weird that Duo wouldn't accept the longer form since it means the same thing as what they suggested. Reported it.