The Passive is not a common old feature of the IE III dialects; it is nevertheless necessary to develop a common modern European grammatical feature based on old endings, like the Conditional.
The -r ending was usual in the Middle Voice, and it either had a special impersonal value or marked the Middle voice. There are thus two features to distinguish their uses: the form and the meaning.
a. The -r after the stem has usually in Europaio an impersonal value, and can be lengthened: -ro, -roi, -renti, -ronti, -rontoi, etc. They are used in the 3. person singular and plural, and the -nt- is added when needed to distinguish the plural; and when the Middle was needed, an -o was added. The primary -i was also added with this aim.
b. The -r after the ending was usual in forms related to the Middle Voice in Latin, Italic, Celtic, Tocharian (and even Germanic, Indo-Iranian and Anatolian). Especially in some European dialects, they replaced the primary Middle endings, and acquired a Middle-Passive value. There was, however, no opposition primary/secondary. In our Europaio system, we have chosen to assign this especially European (Northern) value to these endings, leaving the general forms in -i for the middle.
Note. The older meaning traceable (possibly that of IE II) of these endings are the same, though: impersonal subject or, at least, subject separated from the action.
| 
 
  | 
 
  | 
 PASSIVE  | 
| 
 SING.  | 
 1.  | 
 -(m)ar  | 
| 
 
  | 
 2.  | 
 -sor  | 
| 
 
  | 
 3.  | 
 -tor  | 
| 
 PLUR.  | 
 1.  | 
 -mosr/mor  | 
| 
 
  | 
 2.  | 
 -dhuer  | 
| 
 
  | 
 3.  | 
 -(e/o)ntor  | 
This scheme can be further subdivided in the thematic and athematic paradigms:
| 
 
  | 
 
  | 
 Athematic  | 
 Thematic  | 
| 
 SING.  | 
 1.  | 
 -mar  | 
 -ar, -omar  | 
| 
 
  | 
 2.  | 
 -sor  | 
 -esor  | 
| 
 
  | 
 3.  | 
 -tor  | 
 -etor  | 
| 
 PLUR.  | 
 1.  | 
 -mosr/-mor  | 
 -omosr/-omor  | 
| 
 
  | 
 2.  | 
 -dhuer  | 
 -edhuer  | 
| 
 
  | 
 3.  | 
 -(e)ntor  | 
 -ontor  | 
The passives formed with these endings are only the dynamic ones, though, not the statives, which are formed with the verb es, to be. See § 7.1.3. for more information on dynamic passives.