is "grinded" proper?

<p>is this a real word? is it a proper word? will i be ok using it in my essay?
i know it’s supposed to be ground, but i think that’ll sound retardedly bad in my essay</p>

<p>the snippet:
“for three months, I grinded out the practices and workouts alongside every other wrestler”</p>

<p>ground out the workouts? =/
i mean, will this hurt me?</p>

<p>Try “I spent three months grinding out the practices…” does that work?</p>

<p>oh jeez, the simplest fix in the world =)
can’t believe i didn’t see that -___-
thank you</p>

<p>Just in case you were still wondering, the correct past participle is ‘ground,’ i.e. “I ground the still-smoking cigarette butt under my boot and strode into the night.”</p>