A person can see these things because he already has them. Alternate translation: "What a person has" (See: [[rc://en/ta/man/translate/figs-metonymy]])
This refers to things that a person wants but does not have. Alternate translation: "what a person wants but does not have" (See: [[rc://en/ta/man/translate/figs-metonymy]])
The author speaks of everything that people do as being useless, as if they were trying to control the wind. See how you translated this in [Ecclesiastes 1:14](../01/14.md). Alternate translation: "as useless as trying to control the wind" (See: [[rc://en/ta/man/translate/figs-metaphor]])