確かなことが一つある。

sure; certain; positive; definite; reliable; trustworthy; safe; sound; firm; accurate; correct; exact; If I'm not mistaken; If I remember correctly; If I remember rightly

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 sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

one; for one thing; only; (not) even; just (e.g. "just try it")

to be (usu. of inanimate objects); to exist; to live; to have; to be located; to be equipped with; to happen; to come about