Some translations set each line of poetry farher to the right than the rest of the text to make it easier to read. The ULB does this with the poetry in 4:1-3, 4:5-6, and 4:8-12.
The teacher looks at the oppression in the world and is saddened by it, but he is the king and has the power to change things. He also laments being alone even though he has many wives, children, and concubines. (See: [[rc://en/tw/dict/bible/other/oppress]], [[rc://en/tw/dict/bible/kt/lament]] and [[rc://en/ta/man/translate/figs-irony]])