Inna and her sisters

The Nominalizer إنَّ & her Sisters ( لعلَّ ، أنَّ ، کأنَّ ، لکنَّ ، لأنَّ ) change the subject nominative case marker to the accusative but they leave the predicate in its nominative case. By the way,  أنَّ / إنَّ are called "Nominalizers" because they introduce nominal sentences.

إنَّ الأکلَ لذيذ ٌ.

In fact, the food is delicious.

  قالتْ اُختي أنَّ الأکلَ لذيذ ٌ.

My sister said that the food was delicious.

لکنَّ الأکلَ لذيذ ٌ.

... but the food was delicious.

      إنَّ  is only used in the initial position of a sentence, and following any form of قالَ. Anywhere else you have to use أنَّ. Its meaning, therefore, changes from "indeed/in fact" to "that". Remember that all these particles should be followed by nouns or attached pronoun suffixes. Also notice that  إنَّand her sisters should be followed by the subject or its corresponding attached pronoun.