Deeply inquisitive is correct usage in written English.
You can use it to describe someone who asks a lot of questions or is interested in the depths of a subject. For example, "My son is deeply inquisitive; he always wants to know how things work and why things are the way they are."
Donald Barthelme is another master of that playful, deeply inquisitive form, with stories that always have the feeling of keen scalpel work.
Except that now his deeply inquisitive, German-accented musings refer not to cereal aphids but to the humans who consent to participate in his thoroughly subjective experiments, which stand science on its head, yielding results for the sake of the test subject rather than that of the tester.
This student is high-minded, mystical, deeply inquisitive, pattern-seeking, chronically rootless, goal oriented and dreams of being free.
(Scott) 'GLASS: A PORTRAIT OF PHILIP IN TWELVE PARTS' (No rating, 1 54) Planned as a tribute to the work-obsessed musician Philip Glass, Scott Hicks's affable, admiring movie proceeds genteelly through an intellectually inquisitive and deeply spiritual life.
(Dargis) 'GLASS: A PORTRAIT OF PHILIP IN TWELVE PARTS' (No rating, 1 54) Planned as a tribute to the work-obsessed musician Philip Glass, Scott Hicks's affable, admiring movie proceeds genteelly through an intellectually inquisitive and deeply spiritual life.
In this startling three-dimensional composition, Rubenstein, a naturally inquisitive Jack Russell, more deeply excavates the themes from his earlier "Sit/Stay" series.
I would describe myself as the class dummy, the one who is still the most resistant, the most inquisitive, the least trusting, the most deeply flawed and ridiculous.
They are inquisitive creatures.
Human beings are inquisitive.
"She was curious, inquisitive.
