You will be given a definition of a task first, then some input of the task.
In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

What is a specific type of way you could identify a perfective verb?, Context: The verbs of most aspect pairs differ in one of two ways: by prefix or by suffix. In prefix pairs, the perfective verb has an added prefix—for example, the imperfective psát (to write, to be writing) compared with the perfective napsat (to write down, to finish writing). The most common prefixes are na-, o-, po-, s-, u-, vy-, z- and za-. In suffix pairs, a different infinitive ending is added to the perfective stem; for example, the perfective verbs koupit (to buy) and prodat (to sell) have the imperfective forms kupovat and prodávat. Imperfective verbs may undergo further morphology to make other imperfective verbs (iterative and frequentative forms), denoting repeated or regular action. The verb jít (to go) has the iterative form chodit (to go repeatedly) and the frequentative form chodívat (to go regularly).
Output:
(to write down, to finish writing)