if the sentence says "sori.korean ka pala." it means, the person is apologizing as he thought that you were a Filipino,or any nationality for that matter. pala - means so many things in filipino depending on how you use it,and how you pronounce it. this word could mean the following: ~shovel [san mo nilagay ang pala?] "where did you put the shovel?" ~blessing [ikaw ay pinag-pala] "you are blessed" ~by the way [nga pala...] ~i suddenly remembered [oo nga pala!]

"Sori ha,korean k pala!" is a contracted way of saying "Sorry ha, Korean ka pala". If it is not used with other enclitic markers, "pala" (stress on the second syllable) means "I didn't know, I just learned". "Korean ka" means "You are Korean" so "Korean ka pala" means something like "I didn't know you were Korean". Kumain ka na. You already ate. Kumain ka na pala. So you already ate [I didn't know that] ... I didn't know you already ate [I shouldn't have prepared this dinner for two].

In Filipino "Pala" is either a noun or interjection. It depends how it was used. "Pala" as a noun means Shovel: Example: Hiniram niya ang kanilang pala. She/he borrowed their shovel. "Pala" used as interjection. Example: Ikaw pala. So it's you! (So you're the one!)

in Filipino "k" does not represent as laughing ..

there's actually no direct translation in english for the word "pala". when you're using this word, you're in the state where you feel surprised about learning or remembering something important and true that happened in the past. the expression is based on the explicit fact. consider this: 'kumain ka na pala' (so, you've already had your meal, eh?) 'ah... gano'n pala ha.' (so, that's the real story.) 'ang ibig sabihin pala nito ay...' (the true meaning of this therefore...) 'biglang naglaho ang puti... ay, pula pala' (the white... I mean red, suddenly disappeared.) Sori ha,korean k pala! [oh, I'm sorry, I thought you're (nationality)] in a conclusive manner: Sori ha,korean k pala! (So, you're Korean!) :)