Is 行く stative, continuous or instantaneous? 「今父はタバコを買いに行っています。」


My textbook says 行く is instantaneous (expresses changes from one state to
another) and can only be used to describe the result of a change, not
movements that are currently in progress. But a Japanese native has told me
that it can be used to express an on-going action. For example

> 今父はコンビニにタバコを買いに **行っています** 。

describes the father somewhere in the process of the action.

So, as you can imagine, I'm very confused with all this. Could somebody please
clarify it a bit? Is my textbook wrong?




行っています doesn't express an on-going action in the same way that 走っている might be
running. The sentence means that the father has gone to buy some fags and
hasn't yet returned.

