[[MediaWiki:Movesubpagetext-truncated]] is ungrammatical if these is only 1 subpage. In that case the message becomes "The first 1 subpage for this page are shown below." because are has not been changed to is. The fixed message would be "The first $1 {{PLURAL:$1|subpage|subpages}} for this page {{PLURAL:$1|is|are}} shown below." .

[[MediaWiki:Movesubpagetalktext-truncated]] has the same problem as well and should be changed to "The first $1 {{PLURAL:$1|subpage|subpages}} for the corresponding talk page {{PLURAL:$1|is|are}} shown below.".

Message URL: https://translatewiki.net/w/i.php?title=Special:Translate&showMessage=movesubpagetext-truncated&group=core&language=el