What is the Italian translation of 'You know that'?

Lo sai or Sai che are Italian equivalents of the English phrase "You know that."

Specifically, the personal pronoun lo means "him, it, that, this." The verb sai means "(informal singular you) are knowing, do know, know." The relative pronoun che means "that."

The respective pronunciations are "lo seye"* and "seye keh."

*The sound is similar to that in the English noun "eye."