There are many movies and TV episodes in which a character "crosses his own timeline", sometimes even meeting his past or future self (e.g. The Day of the Doctor). Technically, I should say meeting ...
In season 4, episode 6 - "The Doctors' Daughter" - there is a war going on between the Hath and Humans, and Martha ends up in the base of the Hath. Normally the Tardis would translate the language in ...