"I swim."

Translation: 저는 수영합니다.

[_Regula_]

Why is it sometimes 저는 and sometimes 저가 in the beginning of a sentence?

[IaraMe]

는 and 은 are topic markers whereas 가 and 이 are subject markers. Look up talk to me in korean video on youtube they explain the difference very well.

[JulieCast1]

Don't mind so much about the subject, in Korean you can skip it
Apart i saw a video of a native, and she say that sometimes they don't use the particles

[KelseyKoch6]

I looked it up in google translate. 자는 translated to I am. 저가 translated to self.

[hola_xandra]

I'm wondering why as well.

[SophiaNido]

Hi jam. Whoever you may be. You're weird. Just noticed

[REGaddis]

That horrible moment you realize you've forgotten everything you learned yesterday... :(

[lang864129]

저는 水泳합니다

[Discens]

Literal translation. Swimming. I am swimming cause i am still doing it in this moment.

[TJ76231]

Except that is different. It is present progressive when you add -ing. If someone asked you what you do to relax you would say "I swim" not "I'm swimming"; there is a distinction.

[Duo_Euphoria]

수영해

[SunwoosCloud]

What's the difference of 합니다 and 입니다??

[Duo_Euphoria]

합니다 comes from the verb 하다 (to do) or in this case 수영하다. 입니다 comes from the verb 이다 (to be) for example X is Y (X가 Y입니다). not to be confused with 있다 which also means to be or to exist