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I always hear the word (sokka) when I watch an anime. I think it is like saying (Really?). How is it written?

Hello Tsukinowa,

"Sokka" comes from the Japanese phrase "So Ka" which means "I Understand." It was used in Avatar: The Last Airbender for a main character.

Hi, 「そっか(sokka)」 is from 「そうか(so-ka)」 as Cherry said.
It's 「そう + か」.

「そう( so- )」 basically represents things that comes before.
In English, it looks like [it] or [that] [so].
for example. [I think so]. Same pronounce, it's by chance :D

[そう] is often used in conversation.
I hope you understand what I wanted to say. If you have more questions, contact me anytime !

sokka is Japanese, it is written as:
そっか, 足下

Really? it is "そっか"

そうですか（sou desu ka)→そうか（sou ka）→そっか（sokka)
It's mean " I see." in English. Ms. Cherry's answer " I understand" is correct.

ok some people spelled it
sotsuka
and some spelled it
souka
wonder what the difference is.
and then what compares
souka to wakarimasu?

Yep, "sou (desu) ka" it is. 'Sokka', for short.

The 'ka' particle isn't really meant to make it a question, btw. It's like the German: "Ach so!?" Hence, when I encounter "Sou ka!" in Anime, I translate internally to "I see!" (which is pretty much short for "O, it's like that?! I see!"). There's a built-in realization moment, as it were, followed by the statement that you (now) understand. It's not just the same as wakarimasu! (also "I understand")

Skwer, now that I've learned hiragana (can you tell I'm proud? LOL), I think the 'tsu' in そっか (sotsuka) is just a way to form the double 'k'. So it really just says 'sokka', after all.