"강은 물이 깊지 않지요?"
Translation:The river is not deep, right?
Emphasis on the use of
Adj/Verb + 지요 [or 죠]
Basically, when used as a tag question, it is to seek confirmation from the listener. (Eng. equivalent: right?; Eh?; understood? agreed? etc.)
As a simple question, it is to probe an answer (to get information) from the listener. (Eng. equivalent: true? etc.). The only difference to tag question is the voice inflection used.
In an affirmative sentence, it implies confirmation from the speaker. (Eng equivalent: of course; correct; affirmative etc.)
-지요 verb ending is usually used like an English "tag question"* to seek a response / confirmation from the Listener. [ * tag questions: Is it? Isn't it? Does it? Doesn't it? Correct? Right? etc. ] . So,
강은 물이 깊지 않아요? Isn't the [ water in the ] river deep? (Without tag question)
강은 물이 깊지 않지요? The [ water in the ] river is not deep, is it? (With tag question)
-죠 is actually just a shortened form of -지요, which is comprised of two parts, -지 and the polite ending -요. -지 basically expresses the nuance that the speaker wants the listener to confirm/agree with what they are saying, much like the English tag question. And like the English tag question, it can be meant as a genuine question: “What I’m saying is true, isn’t it?” Or it can be used to express emphasis, a kind of “you know this is true” kind of feeling. For example: “Well, the Sahara is very big, isn’t it. So you had better not get lost there.”
-죠 = -지(요). The "요" ending is just thrown in to make it sound more polite
(1) As question ending -죠? is used to negate a statement and turn ot into a question in order to check the information given by the statement is true (general question) or to seek the listener(s)'s agreement (tag question). The difference is in the voice inflexion at the end of the question.
• as Eng. question tag: right?, agreed? etc. (See @AbunPang's explanation).
강은 물이 깊지 않지요? (Strong inflexion) = The river is not deep, agreed?
• as a general question ending similar to the Eng. Say (Mind telling me) again?"; sure?
강은 물이 깊지 않지요? (Lower inflexion) = Sure the river is not deep?
(2) As a statement ending -죠 is used
• as a reinforcement of fact, equivalent to the Eng amplifier "absolutely", "of course" etc.
강은 물이 깊지 않-죠 = The river is definitely not deep / Of course, the river is not deep.
• to indicate that the fact given is not a single occurrence.
강은 몇 년 동안 깊지 않았-죠 = The river hasn't been deep for years
(3) As an imperative ending (hence only with action verbs), -죠 acts as a tone softener
강은 깊지는 않는데 조심하지요 = The river is not deep, even so go easy.