The phrase "a major purpose" is correct and usable in written English.
It can be used when discussing the primary or significant aim of an action, project, or study.
Example: "The research was conducted with a major purpose of understanding the effects of climate change on local ecosystems."
Alternatives: "a primary objective" or "a key aim".
Indeed, that seemed to be a major purpose of DeVos's Thursday event.
A major purpose of the program is to extract discounts from prescription drug manufacturers.
A major purpose of Social Security was to reduce poverty among senior citizens, and it worked.
A major purpose of the bill is to expand the role of private health plans in Medicare.
A major purpose of the meetings, as described in the discussion guides, is to identify people with "compelling personal stories that illustrate the need for health care reform".
A major purpose, he said, is to help people "communicate about money, sex, child-raising and other difficult issues that come up in their relationships".
A second major purpose of the present study is to focus on entrepreneurs' self-construal as a potential moderator of the relationship between sex and gender identity and between gender identity and business growth intention (see conceptual model in Fig. 1).
If the commission determines that a group's "major purpose" is political, the group is required to register as a political committee and disclose its donors.
After all, if the major purpose of a legislative body is to legislate, what use is a politician who prefers to canvas his district rather than perform his electoral duties?
The major purpose of a term project is to help students apply what they have learnt to a real-world, challenging task.
If one defines religion in a narrow sense, defining its major purpose to influence its adherents to remain loyal to its doctrines and ignore the outer world, the latter would be true.
