These are either adjectives or verbs, which indicate the outcome of an action. gān jìng ‘clean’ is an example of an adjectival result complement. In English these verb-result complements are often translated as verbs which have an inherent process and result meaning (e.g. ‘wash’ in the example above means ‘wash clean’) and the same applies to most of the examples below.
xué shēng bǎ hēi bǎn cā gàn jìng le 。
The student cleaned the blackboard.
sī jī bǎ qì chē xiū hǎo le 。
The driver repaired his car.
tā bǎ nà piān wén zhāng xiě wán le 。
He has finished writing that essay.
 Yip, P. C., Rimmington, D., Xiaoming, Z., & Henson, R. (2009). Basic Chinese: a grammar and workbook. Taylor & Francis.