You can't surprise a Russian with cheif exectutives
Touché

Point well taken.
The most strange thing (well, for me, at least) that you can speak to a person for long time without knowing his/her sex

We have been talking for a month and I don't know for sure if you are a man or woman

It's practically impossible in Russian.
Aha, well that's interesting. Same would be true in Arabic or Portuguese, among others, where you can see by the context.
Lucy Hamilton had the same conundrum with me, but only because some of the posters I have vanquished on the battlefield express their butthurt by referring to me as "she" and "her" ---- as if female were some kind of inferior thing, which I always say speaks volumes about them.
There are indicators in English, but they're very subtle and not at all conclusive. There are many fascinating studies.
From one of them, this graphic gives clues:
So in English it's a matter of contextual indications and not grammar. Notice the recurring themes of on one side, love and (warm) emotions and "cute" and "cooperation", and on the other side recurring themes of "victory" and "vanquish" and "war" and "competition" --- which I'm sure parallel most other tongues, but we don't have, say, separate words for "thank you" depending on whether the thanker is male or female.