The imperative of رَمَى — يَرْمِي follows the jussive-like second-person stem.
Word / formMeaning / explanation
تَرْمِي → تَرْمِthe final yāʾ is removed in the jussive.
اِرْمِactive second-person imperative, formed after removing the imperfect prefix and adding initial hamzat al-waṣl.
لا تَرْمِprohibition, which retains the imperfect prefix because prohibitive lā acts upon the imperfect itself.
Both lose final yāʾ, but the beginnings distinguish an affirmative command from a prohibition.