Bella: Comming is snowwy and,blow is winddy
Correct: The weather is windy and winter is coming.
Explanation: Study about tenses of the verb, it's about to happen in the future. Be careful with spelling [COMING], [SNOWY], and [WINDY].

Bella: Korea children play snowball in winter.
Correct: Korean children plays snowball in winter.
Explanation: Korea that is a place (country). Korean that is a person from Korea. We use the simple present to express the idea that an action is repeated or usual. The action can be a habit, a hobby, a daily event, a scheduled event or something that often happens.

Bella: korea winter is beautiful.
Correct: The winter in Korea is beautiful.
Explanation: Always start your sentence with a capital letter. Don't forget the use of the article THE. A determiner is a word, phrase or affix that occurs together with a noun or noun phrase and serves to express the reference of that noun or noun phrase in the context. That is, a determiner may indicate whether the noun is referring to a definite or indefinite element of a class.

Bella: I like this Korea winter.
Correct: I like winter.
Explanation: Since, it's happening in Korea no need for you to put the place. You can simplify your sentence.

Hello, Bella! Thank you for doing your homework. You're improving and I'm so proud of you. Keep your motivation burning! Fighting, Bella! Thank you! Take care always. ^^

~ Teacher Belle.