 
 <prompt> Wetin be di words wey trader fit use? Based on di question wey dey before dis one, write something wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: ```The verbs of most aspect pairs dey differ for one of two ways: by prefix or by suffix. For prefix pairs, the perfective verb get one extra 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 na-, o-, po-, s-, u-, vy-, z- and za-. For suffix pairs, another infinitive ending dey added to the perfective stem; for example, the perfective verbs koupit (to buy) and prodat (to sell) get the imperfective forms kupovat and prodávat. Imperfective verbs fit undergo further morphology to make other imperfective verbs (iterative and frequentative forms), wey dey show repeated or regular action. The verb jít (to go) get the iterative form chodit (to go repeatedly) and the frequentative form chodívat (to go regularly).``` 