I know making mistakes is okay., I know making mistakes is okay,

but I feel ashamed/embarrassed when I talk to someone I like. but I feel ashamed/embarrassed when I talk to someone I like.

But I think if I were English speaker, I cwouldn't be good at speaking Korean because Iit is difficult to me even though I am kKorean. But I think if I were English speaker, I wouldn't be good at speaking Korean because it is difficult to me even though I am Korean.

I like reading English books and English sentences. I like reading English books and English sentences

because Iit makes me focus on it and make me funlearning and it is fun for me. because it makes me focus on learning and it is fun for me.

sSpeaking one language is boring. Speaking one language is boring.

and I am so embarrassed when I write wrongmake mistakes in sentences within texts. I am so embarrassed when I make mistakes in sentences in texts.

I made so many mistakes while I wereas talking to someone. I made so many mistakes while I was talking to someone.

wWhy would he not study math??? Why would he not study math???

Using multiple question marks (???) is okay here as this is a casual text, but you shouldn't use this in formal writing.

hHe always makes a long face when he does math. He always makes a long face when he does math.

This might be regional, but I find "makes a long face" unusual. I'd probably say "He always looks sad when he does math."