كَمْ كِتَابًا قَرَأْتَ؟
How many books have you read?
كَمْ مِنْ كِتَابٍ قَرَأْتُ!
How many books I have read!
The first construction requests an unknown number and invites a numerical answer. The second declares abundance rather than requesting information. Their translations may look similar, but their communicative functions differ.
Interrogative kam normally expects a count; declarative kam conveys multitude, potentially with wonder or emphasis. Their grammatical constructions, especially the form of the specified noun, also differ.
KindFunctionExpected response
Interrogative kamUnknown number soughtA count
Declarative kamAssertion of multitudeNo numerical answer needed