(12/28/21)

-그는 나의 손을 잡고 있어.He's holding my hand. ✔

-그녀가 나의 펜을 가져갔어.She took my pen. ✔(Punctuation)

-난 내일 도서관에 갈 거야.I am going to the library tomorrow. ✔ (Punctuation)​

(01/04/21)

-넌 그 공을 잡아야 해. You have to catch the ball. ✔ (Punctuation)​​​

-The bird fell to the ground. -> The bird fell on the ground.

-난 내 열쇠들을 떨어뜨렸다.I dropped my keys. ✔ (Punctuation)​

01/06/21)

-넌 아주 많은 종이를 사용하는구나.You use a lot of paper. ✔ (Punctuation)​

She let the puppies play in the garden. -> She lets the dogs play in the garden.

=> Your sentence has a correct grammatical structure, but this has the correct usage/ expression.

-넌 청구서를 지급해야 해. Y​ou have to the bill. -> You pay your bills. (Capitalization) (Punctuation)

=> Corrected : The sentence is corrected grammatically. ​