"Sétálsz."

Translation: You walk.

[_Polimata_]

anybody could explain me ?

[bdori]

"Your are walking" and "you walk" are the same in Hungarian because there's only one present tense. Here is the conjugation:

sétálok = I walk,
sétálsz = you walk (singular),
sétál = he/she walks,
sétálunk = we walk,
sétáltok = you walk (plural),
sétálnak = they walk

Usually you don't have to use the pronoun (you) in the sentence because the conjugation already shows the person.

Did this help?

[_Polimata_]

ja, danke ! . más claro que el agua! gracias.

[GrowingViolet]

I am guessing the imperative form (i.e., instructing someone "Walk!") is different than this?

[bdori]

The imperative form is "Sétálj!" (singular) and "Sétáljatok!" (plural).

[GrowingViolet]

Köszönöm! ☺