So it depends on who you're referring to as "you". If I was talking to you (female), I'd say, "את הולכת", while if you were talking to me (male), you'd say, ״אתה הולך״. The word ״אתה״ is the masculine version of "you" and את״" is the feminine version. Depending on the gender of the object will determine the gender of the verb (in this case הולך or הולכת. Does this clarify a bit?
This was confusing at first. When we are asked to translate "I go" it wants us to us זז, but when it wants "You go", it expects הולך. While זז does mean 'go' it is in the sense of 'depart' as opposed to just moving along, but in this case we have to learn by sentence rather than meaning.
In numerous participles/present tense, the ת- at the end (pronounced -et) is a standard feminine ending, its absence in the same verb will indicate masculine. With nouns, the ת- or the ה- will often do the same, if the noun will take both forms (like most animals). 2 sg pronoun is the reverse. Some things you just to learn by observation. Languages in general are just irritating like that. They weren't invented by computer programmers. [I am assuming you know that ך is just the final form of כ].