With great difficulty. And I can't do it with water. I have to eat something, usually yoghurt or ice-cream, and just as I'm about to swallow it I pop the pill in and swallow them at the same time.
I can and do regularly as does my husband. My oldest son just had to learn how. I started him swallowing mini m&ms. If they didn't go down, they didn't taste bad and he wasn't getting medication he didn't need. He isn't completely comfortable with it and really has to focus on keeping his gag reflex under control but he can do it. He just turned 13. My younger son, age 9, has a very sensitive gag reflex and I have not tried with him yet. That will be a challenge. :-/