Hi Rob,
Prendre (and all its derivatives- apprendre, comprendre, dépendre, entreprendre, surprendre etc...)
is an irregular verb and conjugates differently from regular verbs ending in RE.
The past participle is pris and even in the present tense the first person plural will be -
nous prenons, ( not nous prendons)
so the imperfect will be different even if the future tense looks the same.
Hope this helps!