Link beteween words אָמַן'aman and אֵם 'em

[Glenn2020]

so, for each verbal form you must

1.  identify the root
2. Then identify which stem it is in (Qal, niphal, ...., hithpael, ....)
3.  Then identify which conjugation it is in (Perfect, Imperfect, participle, ....)

In Esther 2:7, it is the Qal stem, participle conjugation

  Glenn