The two basic imperfects are يَرْمِي (active) and يُرْمَى (passive):
PronounActive imperfectPassive imperfect
heيَرْمِييُرْمَى
they two (m.)يَرْمِيَانِيُرْمَيَانِ
they (m.)يَرْمُونَيُرْمَوْنَ
sheتَرْمِيتُرْمَى
they two (f.)تَرْمِيَانِتُرْمَيَانِ
they (f.)يَرْمِينَيُرْمَيْنَ
you (m. sg.)تَرْمِيتُرْمَى
you two (m.)تَرْمِيَانِتُرْمَيَانِ
you (m. pl.)تَرْمُونَتُرْمَوْنَ
you (f. sg.)تَرْمِينَتُرْمَيْنَ
you two (f.)تَرْمِيَانِتُرْمَيَانِ
you (f. pl.)تَرْمِينَتُرْمَيْنَ
Iأَرْمِيأُرْمَى
weنَرْمِينُرْمَى
Recognition: the active singular retains a final yāʾ, whereas the passive singular ends with alif maqṣūrah. The person-prefix by itself does not tell you whether a form is active or passive; compare the vowel pattern and final weak letter.