So you can write:
En magas vagyok - I am tall - with the pronoun and the verb
Magas vagyok - I am tall - with just the verb
Oe magas - he is tall - just the pronoun without the verb, like Russian
but not, in normal usage
oe magas van - he is tall - with the pronoun and the verb
magas van - he is tall - with just the verb
I can't find much out besides the fact that that is how you do things in Hungarian. Has is always been done that way? If not when did only using the pronoun with no verb come in for the 3rd person? Did people ever use this construction for other grammatical persons in the past? Is there any particular reason for it only being the 3rd person, or is it just one of those unexplainable quirks?