The Present-Future Conjugation

The Present tense of Imperfective verbs uses the same endings as the Future tense of Perfective verbs. This is an effect of verbal aspect since Perfective verbs indicate actions which are successfully completed once regardless of their tense. Since perfective verbs imply completion of an action, they can have no present tense since if an action is completed, it's over and can't be going on presently.