In our first years of learning Russian we spend a lot of time learning conjugation and declension, trying to figure out how to weave sentences together with subjects and direct objects and prepositional phrases. It's an amazing grammatical dance that has its own beauty, though perhaps it takes ten years before one really sees the beauty part... Anyhoo, so you take your first trip to Russia, and you are braced to collide with strange cases and unreal conditional clauses and sentences that last longer than Kafka's, and then you are stunned to learn that it's the really short sentences with nothing but the nominative case that entirely floor you.

For instance, yesterday morning I was in my currently favorite eating place, and I heard the following conversation:

I can pretty well guarantee you that right now first- and second-year readers are thinking "What the heck?" The conversation is between a woman customer (blue lines) and the cashier (yellow lines). Spend a minute or two to see if you can figure out what the heck they are talking about, then click 'read more' for a line-by-line explanation.

Треугольник — means triangle. A triangle is a triangular Tatar pastry that is usually stuffed with meat and potatoes and onions. In this line the customer is stating what she wants.

Вы здесь будете? — is an elliptical sentence, which means some words are left out. In this context it means "Will you be eating here?"

С собой — is also an elliptical sentence. In this context it means "I will take it with me." In other words, the customer will not be eating in the cafe.

Нагреть — is also an elliptical sentence. In this context it means "Shall I warm it up for you?"

Нет — this one is simple. No means no.

So if you were translating a novel into English from Russian, and that dialog was a part of the novel, it would be best to translate it something like this:

Although the please and thanks are not in the original, the Russian conversation is entirely neutral; the customer and the cashier are not at all hostile to each. To catch that same tone in English, you need to supply the politeness phrases.

I suppose we could also do something like this:

But think about this for a minute. If you saw that version in the book, what would you assume about the context? I think I would assume that the cashier was in a hurry, and that the customer had a bunch of people in line behind her, and that they both knew that time was short and orders had to be placed quickly, like in a New York deli during the lunch rush. That wasn't the case when I heard the original conversation. There was no one else in line. It was early in the morning and things were just getting off to a pleasant start. There was no rush at all. So in a professional translation that captures both the lexical information and the emotional information of the dialog, the English version with the please and thanks is better.