Can someone explain the differences between v-ていく and v-てくる for me. I know that they both express some kind of ongoing action (like a place getting crowded). For example, what's the difference between 込んでいく and 込んでくる, or is it even possible to use both of these. Also, do you generally use kanji to write these?
Most of the examples I can think of use v-てくる, like 雨がやんできた, or 空が明るくなってきた. How does the meaning change if I use いく instead?
Edit: changed て行く／て来る to the more proper ていく／てくる.