scio

Scio, scire, scivi, scitum is fourth conjugation. It is knowledge of a fact, so it takes an accusative with an infinitive for a statement and the subjunctive for an indirect question - scio te venire, "I know you are coming"; scio quid velis, "I know what you want".

Three Latin verbs cover what English calls knowing, and they are not interchangeable. Scio is knowing that something is so; cognosco is finding out and thereby coming to know; nosco in the perfect, novi, is being acquainted with. The formal trap is the imperative: scio has no present imperative at all, so the sci a learner would build from scire does not exist; the form Latin actually uses is the future imperative scito, "know thou". Family: nescio, conscius, conscientia, scientia, scilicet. English science, conscience, conscious, prescient, omniscient; Spanish saber comes from sapio, not from scio, so do not guess from it.