Fix #4, 5, 8, 10 and 13

README.md

@@ -11,16 +11,16 @@ This is a hands-on tutorial on how to learn git.
 1. It is raining when I got home last night.
 2. My sister is annoying today, but usually she is nice.
 3. I have not ate anything today.
-4. If I am a child, I would play outside.
-5. Everyone have seen that movie.
+4. If I was a child, I would play outside.
+5. Everyone has seen that movie.
 6. If we will be late, they will be angry.
 7. My father is thinking that I should stop smoking.
-8. Look! It is snow.
+8. Look! It is snowing.
 9. I fell asleep while I watched TV.
-10. I have lived in Canada since 10 months.
+10. I have lived in Canada for 10 months.
 11. There is a warm country.
 12. I have not an iPhone.
-13. I haven’t ever been to Korea.
+13. I have never been to Korea.
 14. The students have a good time in class today.
 15. John probably isn’t going to come to school tomorrow.
 16. If the world ended tomorrow, I will be very sad.