추워요 vs 춥네요 vs 춥지요
I'm trying to understand the nuanced differences with the 네요 and 지요 endings.

If I am on the phone with a friend and they ask about the weather, I could respond with 추워요 to give them a simple answer or with 춥네요 if it's colder than I thought or I was expecting warm weather, but I wouldn't use 춥지요 because they aren't with me and so they don't know what the weather is... 맞아요?

But if I am standing next to a friend, I wouldn't use the obvious 추워요, but would instead use 춥죠 because my friend already knows it's cold and I'm just reaffirming it, right? Could I also use 춥네요 with my friend if we weren't expecting it to be this cold?

Also, in general, can the -네요 and 지요/죠 forms be used as either questions or statements? A lot of the examples I see with 지요 include "isn't it?" in the translation because the speaker is kind of asking for confirmation. But the way I say this in English - "It's cold, isn't it?" - I'm not really looking for an answer.

Question

추워요 vs 춥네요 vs 춥지요
I'm trying to understand the nuanced differences with the 네요 and 지요 endings.

If I am on the phone with a friend and they ask about the weather, I could respond with 추워요 to give them a simple answer or with 춥네요 if it's colder than I thought or I was expecting warm weather, but I wouldn't use 춥지요 because they aren't with me and so they don't know what the weather is... 맞아요?

But if I am standing next to a friend, I wouldn't use the obvious 추워요, but would instead use 춥죠 because my friend already knows it's cold and I'm just reaffirming it, right? Could I also use 춥네요 with my friend if we weren't expecting it to be this cold?

Also, in general, can the -네요 and 지요/죠 forms be used as either questions or statements? A lot of the examples I see with 지요 include "isn't it?" in the translation because the speaker is kind of asking for confirmation. But the way I say this in English - "It's cold, isn't it?" - I'm not really looking for an answer.

Answer

I'm trying to understand the nuanced differences with the 네요 and 지요 endings.

If I am on the phone with a friend and they ask about the weather, I could respond with 추워요 to give them a simple answer or with 춥네요 if it's colder than I thought or I was expecting warm weather, but I wouldn't use 춥지요 because they aren't with me and so they don't know what the weather is... 맞아요?
☞ 맞아요.^^'

But if I am standing next to a friend, I wouldn't use the obvious 추워요, but would instead use 춥죠 because my friend already knows it's cold and I'm just reaffirming it, right? 
☞ 맞아요.

Could I also use 춥네요 with my friend if we weren't expecting it to be this cold?
☞  Yes, you can.
(생각보다) 춥네요 = It's cold (than we expected)

Also, in general, can the -네요 and 지요/죠 forms be used as either questions or statements? 
☞ The ending, -죠(which is short for -지요) can be used in both.
☞ The ending -네요 is only used in plain statemens.

A lot of the examples I see with 지요 include "isn't it?" in the translation because the speaker is kind of asking for confirmation. But the way I say this in English - "It's cold, isn't it?" - I'm not really looking for an answer.
☞ Yes, it is. it works like "Tag Questions" in English.

\^o^/

Answer

~네 ending means you are surprised. 춥네- wow it is cold/ (I am so surprised) It is cold
~지 ending means reassurance; stating the obvious; or agreeing. It depends on context. 춥지(?)- It is (obviously)cold/ It is cold(right?)/ (yes, I agree that) It is cold