Here's why:
* Regular verbs form their past tense and past participle by adding "-ed" (e.g., walk, walked, walked).
* Irregular verbs have unique past tense and past participle forms that don't follow the standard "-ed" rule.
The verb "blow" has these forms:
* Present tense: blow
* Past tense: blew
* Past participle: blown
As you can see, the past tense and past participle forms ("blew" and "blown") don't follow the regular verb pattern.