* Study: This is the most common and general noun form. It refers to the act of applying the mind to learning or thinking.
* Example: "He spent hours in study for the exam."
* Studies: This is the plural form, referring to multiple areas of learning or research.
* Example: "She excelled in her studies."
* Student: This refers to a person who is studying.
* Example: "The students were all working hard in the library."
* Scholar: This refers to a person who is devoted to studying a particular subject.
* Example: "He was a respected scholar in the field of history."
* Research: This refers to a systematic investigation into a subject to establish facts and reach new conclusions.
* Example: "The scientists conducted extensive research on the new drug."
The best noun form to use depends on what you're trying to convey.