How do you say "He is really good at playing soccer"?
Is it:
El es jugar el fútbol muy bien.
How do you say "He is really good at playing soccer"?
Is it:
El es jugar el fútbol muy bien.
Who would use a high-brow adverb like 'realmente' in such a casual context? "Realmente" is a big word in Spain, and it is plausible that the suggestions given above are influenced by the overuse of the word "really" in English-speaking cultures.
Try, "Es muy bueno jugando a fútbol" or "es muy buen jugador de fútbol."
Even more natural: "Juega de maravilla." Or, "Da gusto verle jugar."
"Se le da bien/mal X" is a construction in Spanish that means "(s)he's good at X". (Note: Don't try to translate it literally.)
So, in this case,
Se le da muy bien el fútbol.
Although the exact translatation for that is:
Él es realmente bueno jugando al soccer.
I would like to say that, we don't use soccer that much, we prefer to use Fútbol (football) because in latin America and Spain we play more soccer than the sport you know for football in USA. Another way to say the same could be
Él es un jugador de fútbol realmente bueno.
(He is a really good soccer player.)
In addition to the dársele bien structure that user3206227 gives, if the thing one is good at a verb, the structure "X is really good at Ying" can also be rendered quite naturally into Spanish as "X YX muy bien" or similar.
So in your example, you would have:
Él juega al fútbol muy bien