OET interlinear ECC 2:20

uW Translation Notes:

Note 1 topic: figures-of-speech / metaphor

לְ⁠יַאֵ֣שׁ לִבִּ֑⁠י

to,make_despair (Some words not found in UHB: and,I_turned I to,make_despair DOM heart_of,my on/upon/above/on_account_of//he/it_went_in all/each/any/every the,toil which,I_have_toiled below/instead_of the,sun )

The word heart here represents a person’s feelings and emotions. Solomon means that he caused himself to feel hopeless. You may have a comparable expression in your language, or you could state the meaning plainly. Alternate translation: [to make myself feel hopeless]

Note 2 topic: figures-of-speech / idiom

תַּ֥חַת הַ⁠שָּֽׁמֶשׁ

below/instead_of the,sun

Solomon is using under the sun as a common expression of the culture to mean “in this life.” If this phrase does not have that meaning for your readers, you could use a comparable expression from your language that does have that meaning, or you could state the meaning plainly.

Note 3 topic: writing-pronouns

וְ⁠סַבּ֥וֹתִֽי אֲנִ֖י

and,I_turned I

Solomon is stating the pronoun I separately, even though the verb translated as turned already includes this meaning. He is doing that to emphasize that he himself is the one who felt this despair. If a speaker of your language would use an explicit pronoun for the same purpose, you may want to use that construction in your translation. If not, your language may have other ways of showing the meaning here.