[verb] + 懂 / 清楚 / 错 / 掉 / 住 / 开 / 上 / 下
[subject] + [verb] + [complement] + 了 + [object]
[subject] + 没 + [verb] + [complement] + [object]
A result complement is a verb or adjective placed straight after the main verb to say how the action turned out. 完, 到, 见 and 好 have their own point; these eight are the next ones you meet.
开 separates and 上 joins, so the same door is opened with 打开 and shut with 关上.
A result that didn't come about takes 没 in front of the verb, and the 了 goes.
To say you can't understand, the complement takes 不 in the middle: 听不懂. That is the potential complement.
Verb and complement stay together. 了 and the object follow the pair.