In English there is a difference. To be 'by' something is only to be in the general vicinity, whereas 'beside' or 'next to' is more specific and closer. I imagine that Hungarian also makes a distinction, and that the word here means 'beside' rather than 'by '.
English has another commonly used word for this use, "alongside" but I don't believe it is accepted either.
I don't think you can use "alongside" about humans. It only works for other cars, or boats, or piers, or trains, or railway platforms, or other elongated transportationary things.
Well, you can say things like "The Conservatives worked alongside the Socialists to get the legislation passed."
Maybe you need to be referring to a group of people in order to use "alongside"?
In this case "alongside" is metaphorical rather than physically literal. In any case nowadays it would be more common to use "with."
I had not heard of the notion that 'alongside' should not be used in relation to humans, so I checked the dictionary meaning. Have a look at this link to see if you agree that 'alongside' covers many applications, people included. https://en.oxforddictionaries.com/definition/alongside I would still use this word in the instance being discussed, and in multiple others.