어서 일어나다

wake up or stand up

일어나다 covers waking, getting to your feet, and things happening, and all three appear here. 물을 마시고 싶어서 일어났어요 is waking because you wanted water; 다리를 쭉 펴서 일어난다 is straightening your legs and standing; 만나서 일어나는 그런 얘기예요 is a story of what happens when people meet. The -아서/어서 clause gives the cause or the movement that leads into it.

Register: neutral