そのことは確信する。

that (something or someone distant from the speaker, close to the listener; actions of the listener, or ideas expressed or understood by the listener); the; um...; er...; uh...

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

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

conviction; belief; confidence