KJV: And I gave my heart to seek and search out by wisdom concerning all things that are done under heaven: this sore travail hath God given to the sons of man to be exercised therewith.
NASB: And I set my mind to seek and explore by wisdom concerning all that has been done under heaven. It is a grievous task which God has given to the sons of men to be afflicted with.
KJV: I sought in mine heart to give myself unto wine, yet acquainting mine heart with wisdom; and to lay hold on folly, till I might see what was that good for the sons of men, which they should do under the heaven all the days of their life.
NASB: I explored with my mind how to stimulate my body with wine while my mind was guiding me wisely, and how to take hold of folly, until I could see what good there is for the sons of men to do under heaven the few years of their lives.
KJV: Then I looked on all the works that my hands had wrought, and on the labour that I had laboured to do: and, behold, all was vanity and vexation of spirit, and there was no profit under the sun.
NASB: Thus I considered all my activities which my hands had done and the labor which I had exerted, and behold all was vanity and striving after wind and there was no profit under the sun.