الْمُبْتَدَأُ

The subject مُبْتَدَاٌ of a nominal sentence is most of the time definite and in a state of raf  مَرْفُوْعٌ . 

There are three agents that effect the subject when they come before it namely  إِنَّ وَأَخَوَاتُهَا , كَانَ وَأَخَوَاتُهَا  and  ظَنَنْتُ وَأَخَوَاتُهَا