وَقَدْ تُسْتَعْمَلُ صِيغَةُ النِّدَاءِ فِي غَيْرِ مَعْنَاهُ
The vocative form may also be employed for a purpose other than its basic meaning.
The basic force of a vocative is to request attention; however, the addressee may already be attending. In that case the same form can serve another purpose: prompting complaint, highlighting a personal qualification, seeking aid, or expressing amazement.
Grammatical form and communicative purpose must be distinguished. The vocative construction remains recognizable even when the speaker’s main intention is not to secure a new act of attending.
PurposeContextual cueIntended effect
Literal addressAttention is requiredSecure attention
InducementComplaint already under wayEncourage further complaint
SpecificationSpeaker’s quality mattersHighlight a qualification
InvocationAssistance is neededAppeal for help
Wonder/lamentStriking circumstancesExpress wonder or grief