I am struggling with the ndesu - nda form. I understand that in most instances this is used to ask or give more context / an explanation. In practical use I don't understand the difference between questions with or without this form.
For example: nani wo shite imasu ka? What are you doing VERSUS nani wo shite iru ndesu ka? What are you doing / What is it that you are doing?
Isn't it obvious that in the first question I also ask an explanation / reason / context? What is the difference? I have the same question for the answer part.
Watashi wa terebi wo mitte imase - I am watching TV VERSUS watashi wa terebi wo miru ndesu. I am watching TV / It is that i'm watching TV.
I really don't see the difference in meaning; I am sorry for this. Hopefuly someone can help me.
どうも ありがとう ございます