"The worker is waiting outside."
Translation:A munkás kint vár.
Some verbs take a mandatory argument that can be "turned off" with a suffix. I can't think of many examples, vár (valamit/valamire) and épít (valamit) are such verbs for sure. Forms of vár always imply you are waiting for a very definite event/person, várakozik sounds more "waiting around", with no well-defined goal.
It's even more plastic with épít. I'm not sure about whether you can answer a question like "What are you doing?" by saying "I'm building." but in Hungarian, "Építek." without an object sounds almost nonsensical. If you want to express that you are taking small steps at building something that may or may not get finished eventually and it doesn't matter what it is from the answer's point of view - use "építkezek/építkezem".