The imperative form of Japanese of verbs is constructed differently depending on whether the verb is a -ru, -u or irregular verb.
-ru verbs
For -ru verbs, the stem remains unchanged. For example, to make the passive form of 食べる, simply use the same stem as in the other forms, followed by the verb ending られる.
食べ・る → 食べ・られる
-u verbs
With -u verbs, the -あ stem (ない stem) is used.
書く → 書か…
As we saw with the -nai ending, in verbs ending in う itself, う changes to わ . e.g:
買う → 買わ…
Onto this stem, add the verb ending れる.
書か・れる
言わ・れる
Romaji
In a similar way as with the conditional form, it gets very simple if a verb is rendered in Romaji. For nearly all verbs, just change the final -u to –areru.
taberu → taberareru
kaku → kakareru
nomu → nomareru
However, be careful of verbs ending in u after a vowel.
iu → iwareru
kau → kawareru
Irregular verbs
The imperative form of する is される.
The imperative form of 来る is 来られる（こられる).
行くfollows the same rule as for -u verbs, with an imperative form 行かれる.