How do english speaking people know that acquaintances of their's talk to them as if the two were friends?

We don't find it necessary. We know whether someone is a friend or acquaintance from our interactions with them.

Same as the tenses. You don't. Never needed to "tell story of the past that was telling of the future, yet still in the past". As in Czech. All that is just one tense.

Hi mate 😊