Questions & Answers about Chłopiec kichnął pięć razy.
Why use the perfective kichnął if he sneezed five times? Doesn't repetition require the imperfective kichał?
This is a great nuance of Polish aspect! While the imperfective is used for habitual or unbounded repetition, you can use a perfective verb (especially a "single flash" semelfactive verb ending in -nąć) with a specific number if you view the whole event as a single, completed package. Chłopiec kichnął pięć razy means he did a quick, bounded sequence of five sneezes and finished. Using the imperfective kichał pięć razy is also grammatically possible, but it would sound more like a drawn-out process rather than a quick, completed event.
What is the imperfective pair for kichnąć, and how was this perfective form created?
The imperfective verb is kichać (to sneeze). To create the perfective form for a single, instantaneous action (a semelfactive verb), we take the stem, drop the -a-, and add the suffix -nąć. This gives us kichnąć (to sneeze once).
Why is there an -ą- in kichnął, but if the subject were a girl it would be kichnęła?
Verbs ending in -nąć undergo a vowel shift in the past tense. The nasal vowel -ą- appears before the masculine singular past tense marker -ł (e.g., on kichnął). However, before any past tense marker that contains a vowel—like the feminine -ła, neuter -ło, or plural -li / -ły—the -ą- softens to an -ę- (e.g., ona kichnęła, one kichnęły).