A S S O O N A S / U N T I L
As soon as is used when we want to describe one event starting immediately after another.
As soon as + simple past + simple past
*** As soon as the police came, the murderer started to run away.
As soon as + simple present +simple present / will future
*** As soon as she enters the house, she turns on the lights.
Until is used to refer to the end of a period of time.
*** I’ll wait for you until two o'clock.
*** We travelled by car until the petrol ran out.