Are these sentences correct?
1. I think Chinese is interesting but I feel that Chinese grammar is a bit hard.
我思的中文有意思但是我觉的中文语法一点儿难。

2. Last year on April 12th at 5:30pm she reviewed Chinese very fast.
她去年四点十二号五点半中文复习得很快。

3. How about you teach me to write characters?
你教我字，怎么样？

4. You write Chinese way too slowly/You speak Chinese way too slowly.
你中文写得太慢。
你中文说得太慢。

5. How did you come here?
你来这儿怎么？

Question

Are these sentences correct?
1. I think Chinese is interesting but I feel that Chinese grammar is a bit hard.
我思的中文有意思 但是我觉的中文语法一点儿难。

2. Last year on April 12th at 5:30pm she reviewed Chinese very fast.
她去年四点十二号五点半中文复习得很快。

3. How about you teach me to write characters?
你教我字，怎么样？

4. You write Chinese way too slowly/You speak Chinese way too slowly.
你中文写得太慢。
你中文说得太慢。

5. How did you come here?
你来这儿怎么？

Answer

1. I think Chinese is interesting but I feel that Chinese grammar is a bit hard.
我思的中文有意思 但是我觉的中文语法一点儿难。
我思是中古中文 (classical Chinese) as in 我思故我在 (I think, therefore I am) (Je pense, donc je suis.)
In modern Chinese vernacular, you are going to want to use:
我想 or 我認為
我認為中文有意思(or 很有趣) 文法有點難

2. Last year on April 12th at 5:30pm she reviewed Chinese very fast.
她去年四点十二号五点半中文复习得很快。
她去年四月二十五號
3. How about you teach me to write characters?
你教我字，怎么样？
你教我認字
4. You write Chinese way too slowly/You speak Chinese way too slowly.
你中文写得太慢。
你中文说得太慢。

5. How did you come here?
你来这儿怎么？
你是怎麼來的

Answer

1. I think Chinese is interesting but I feel that Chinese grammar is a bit hard.
我 觉得 中文有意思 但是我 感觉 中文语法 有 一点儿难。

2. Last year on April 12th at 5:30pm she reviewed Chinese very fast.
她 在 去年四月十二号五点半 中文复习得很快。

3. How about you teach me to write characters?
你教我 写/认？（need a verb） 字，怎么样？

5. How did you come here?
你来这儿怎么？
你怎么来着的？