痛くなったり grammar?


I'm having trouble understanding 痛{いた}くなったり (itakunattari). Appears to be
itakunai + the "tari" adverb thing. But then why is it 痛{いた}くなったり and not
痛{いた}くなたり




As a comment says, 痛くなる has two parts - 痛い + なる, meaning something becomes a
pain. なる + たり is なったり, since it's too mouthful to say なたり, just like the past
tense for なる is なった not なた

