You can identify this passive version of פִּעֵל by applying the following rules of thumb:

There is almost always a dot of emphasis – a דָּגֵשׁ – that appears in the second letter of the root. Two exceptions: when the root is composed of four letters (usually a foreign root), and when the second root letter makes a guttural sound, making such emphasis difficult for native speakers to pronounce (such as the letter ע in פֻּעַל).

In the past tense, the three letters of the root appear first in the word, but unlike the קל form, there is almost always a דגש in the second letter of the root, as in הַכֶּסֶף שֻׁלָּם (the money was paid).

In all three major tenses, there is an oo-ah or oh-ah vowel rhyming pattern.

Witness these patterns as you review the chart below, which lays out all the possibilities of the verb מְדֻבָּר (spoken of) in past, present and future tenses: