Quote Originally Posted by Medved View Post
Because we use "я пойду" or "я побегу", this kind of thing in the meaning of an immediate action, instead of a planned action, like "ну, я пошёл". This translates into a "shall-phrase", like "Shall I go now?" = Ну, я пошёл уже? or Ну что, пойду я уже.

This is not quite the same as "I will go" = Я пойду (на концерт завтра)
This is what I'm trying to say. According to your logic, someone learning Russian should memorize the translation:
"я пошёл" = "I shall go"
Yes, it might be appropriate to translate it like that in certain contexts, but memorizing a tranlsation like this is ridiculous.

Or another example. You said:
Мне нужно = I need
Я вынужден = I have to (I'm forced to)
Я должен = I must
There's no difference in meaning in English between "I need to" "I have to" and "I must", but the three Russian phrases all have different meanings.