Inna and its five sisters govern a nominative khabar and an accusative ism.
The khabar may be single-word, clausal or quasi-clausal. The source prohibits ordinary fronting before the ism, while allowing a fronted locative expression.
The two core source examples are إِنَّ زَيْدًا قَائِمٌ and إِنَّ فِي الدَّارِ زَيْدًا.