私はそこへ行ったことを後悔している。

I; me; private affairs; personal matter; secrecy; selfishness

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

there (place relatively near listener); there (place just mentioned); that place; then (of some incident just spoken of); that (of point just raised); you

indicates direction or goal (e.g. "to")

to go; to move (in a direction or towards a specific location); to head (towards); to be transported (towards); to reach; to proceed; to take place; to pass through; to come and go; to walk; to die; to pass away; to do (in a specific way); to stream; to flow; to continue; to have an orgasm; to come; to cum; to trip; to get high; to have a drug-induced hallucination

thing; matter; incident; occurrence; event; something serious; trouble; crisis; circumstances; situation; state of affairs; work; business; affair; after an inflectable word, creates a noun phrase indicating something the speaker does not feel close to; nominalizing suffix; pretending to ...; playing make-believe ...; alias; aka; nickname; alternative name; also known as

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

regret; repentance; remorse