1. i have a cat. our family adopted it 4 years ago
2. i've never kept rabbit and snake as a pet. To keep snake as a pet is quite dangerous.
3. i had learned how to ride a bicycle from my mom, when i wS little.
4. i will build a tree house for my 3 years old nephew.
5. when i was in elementry school, i made a scrapbook for some artucles.
6. my friend's younger brother taught me how to play chess.
7. my mom is good at painting house.
8. i never used to play chess, but now i plasy chess.
9.my aunt's husband didn't use to collect forign money. but he collect it. Does this sound natural?

1.) Capitalize all the letters that start off a sentence. Also capitalize 'I' because it is a noun that is you similar to that of a name.

2.) Read what I said at 1.) Dude, this horrible, lol but I'll try and help. "I've never kept a rabbit nor a snake as a pet. To keep a snake as a pet would be dangerous." Read this sentence that I wrote. You have many things to learn still in regards to English.

3.) "I've learned how to ride a bicycle by my mom when I was little." Dude, you have to capitalize the beginning of the letter in a sentence. Read more about English grammar and correct English syntax because this is just horrible!

4.) "I will build a tree house for my three year old nephew." You don't say "years" when you're describing someone else's age.

5.) What the heck is an "artucles"?

6.) Capitalize your sentences, dude.

7.) Capitalize your sentences, dude.

8.) "My aunt's husband didn't used to collect foreign money but now he collects it"

This sounds horrible. However, I was nice and I put "a little unnatural". If you can buy or for free read English grammar and syntax books.