I don;t know about the subjunctive, but as far as active indicative imperfect:
Vocare - to call
imperfect active indicative:
vocabam - i was calling
vocabas - you were calling
vocabat - he/she/it was calling
vocabamus - we were calling
vocabatis - you all were calling
vocabant - they were calling
Unfortunately I don't know the subjunctive mood yet, just the active and passive of the indicative.