There's no direct translation of "sino" to English. We have to use some kind of phrase to communicate the same idea. What you suggest accurately conveys the meaning of this Spanish sentence. I've seen Duo translate "sino" variously as "but," "but rather" and "rather." None of those sound quite right to me when used simply. And my natural inclination would be to reverse the two clauses and say, I drink water, not milk. Still, if it isn't grammatically incorrect to just replace "sino" with "but," "rather" or something similar, that's probably the closest translation.
"sino" is an adversative conjunction used to set two ideas/concepts in opposition. In Spanish, you start with a negative and follow with an affirmative, connected by "sino." There are other constructions that use "sino," but I haven't encountered them in Duo yet.
Masterofgreen's answer is misleading. In English, commas are sometimes necessary before a conjunction and sometimes they are not. It depends. If the conjunction is being used to join two independent short sentences, such as "I tried" and "I failed," then you don't need a comma because each of these sentences is very, very short. Example of two very short sentences joined by a conjunction in order to form a compound sentence: I tried but I failed. (A compound sentence is defined as two complete/independent English sentences joined by conjunctions like "but," "or," "and.") With short sentences like this, the comma is optional.
Example of a short COMPOUND SENTENCE: Mary and Susan are friends, and they went to a dance. It should be noted that even this simple compound sentence is long enough that the comma is preferred, although it can be omitted in sentences of this length and simplicity.
If the conjunction is being used to connect a compound subject, a compound predicate, or a compound object of a preposition, then a comma is unnecessary as long as the compounded part of speech has only two elements. Example of a COMPOUND SUBJECT: MARY AND SUSAN are friends. Example of a COMPOUND PREDICATE: They WENT to the party AND DANCED all night. Example of a COMPOUND PREPOSITION: Did you hear the story OF the OWL AND the PUSSYCAT?
From what I have seen in immersion, this English comma rule is not a rule of Spanish grammar. In Spanish, there is usually no comma used when a sentence has two parts that can be translated into two separate English sentences. For example: Quiero dinero y ahora lo quiero. (I want money, and I want it now.) No quiero mucho dinero sino me quiero un trabajo. (I don't want much money, but I do want a job.)
I do want to add that when an English sentence has a series in it, the series is separated by commas. A series is defined as a row of at least three words that are the same part of speech. There are noun series: The CAT, DOG, and BIRD are all pets of the same person. I am the owner of the CAT, DOG, and BIRD. There are verb series: The animals EAT, SLEEP, and DEFECATE every day. There are adjective series: I want the BIG, WHITE, ROUND, and FLAT button. There are adverb series: He spoke TIRELESSLY, ENDLESSLY, and RECKLESSLY. One final twist: Between many English speakers and writers, there is a longstanding disagreement about whether or not to omit the last comma in a series. Whatever your style is, just be sure to be consistent about how you apply the rule.
They are not interchangeable. Sino is mainly used if the main clause is a negative statement and the subordinate clause is contrasting that, think "but rather". Pero is used for all other cases of "but".
So you can write these sentences, which express the same idea:
- No bebo leche sino agua.
- Bebo agua, pero no leche.
You're correct, the Spanish conjunctions y, o, and sino do not need commas. But also in English "and" and "or" do not require the use of a comma by themselves. The comma rules in English are pretty spongy and complicated and I still (after 15 years of learning it) cannot make sense of them. :´)
Of course there are some sentence constructions that make a comma necessary (or even just preferred) in English. I did not say that commas before those words weren't allowed at all. Rather, I was talking about the conjunctions in their natural surroundings. The default, so to say.
On that note: down with the Oxford comma! Even though I'm using it.
It may not be the best way to say this in English, but consider:
1. sino is very commonly used in oppositional statements in Spanish
2. To match the Spanish construction, which must begin with the negative, the English sentence structure seems a little odd
3. If you can make sense of, "I drink water rather than milk," then you should be able to understand "I don't drink milk, rather (I drink) water" - the parenthetical is not necessary. I inserted it merely to make the meaning more obvious. Also, I think sino is closer to "(but) rather" than simply "but."
Sino has to be used if the first clause is talking about what isn't true, and the second is talking about what is true instead. You can translate it as "but instead" or "but rather".
- No quiero ir a casa sino quedarme . - I don't want to go home, but instead (I want to) stay.
If you switch the clauses, putting the positive one first, you have to use pero again:
- Bebo agua pero no leche. - I drink water, but not milk.
Sin is the word that means "without". Sino is a different word.
Sino is a conjunction that translates as "but instead" or "but rather" in English. It is used when the first clause of your sentence is negated and in the second clause you say what is true instead. "I do not drink milk, but instead I drink water."