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).

Question: How many ways can a verb in an aspect pair differ?
Answer: two ways

Question: What does a perfective verb have added in prefix pairs?
Answer: an added prefix

Question: What is added to the ending in suffix pairs?
Answer: different infinitive ending

Question: What can imperfective verb undergo to make other imperfective verbs?
Answer: further morphology

Question: What type of action can second level morphed imperfective verbs denote?
Answer: repeated or regular action

Question: What are the most common suffixes?
Answer: Unanswerable

Question: What is added to the perfective stem in a prefix pair?
Answer: Unanswerable

Question: What might prefixes have happen to make other imperfective verbs?
Answer: Unanswerable

Question: What kind of action can morphed prefixes be a sign of?
Answer: Unanswerable

Question: In what two ways are perfective stems different?
Answer: Unanswerable