Aug. 20

2. 我有小猫。/小猫我有。
I have a kitten.
我有一只小猫。

3. 他的姐姐和哥哥是英语老师。√
His older sister and older brother are English teachers.

4. 你回来吗?√
Are you coming back?

5. 他们没有钱。
    他们没有了钱。<< pretty sure that's wrong..
    They have no money.
    They had no money.
他们没有钱了。

6. 他是好老师。√
He's a good teacher.

7. 他认识女孩的是大学生。
He knows a girl who's a college student.
他认识了一个大学女孩儿。

8. 我是人的喜欢音乐/我是人的音乐喜欢。
音乐(我)喜欢。/我喜欢音乐。
I'm a person who[that] likes music.
I like music.
我是一个喜欢音乐的人。

我喜欢音乐。

9. 我们它认识。/它我们认识。
We know it.

我们认识/知道它。

Aug. 20

Put "了” in the end and it becomes a sign of pass tense which I'm sure you've already known. 
    They have no money.
    They had no money.

6. 他是（个）好老师。You can either use "个” or not.
He's a good teacher.

7. 他认识了一个女孩的是大学生。
He knows a girl who's a college student.

8. 我是一个人的喜欢音乐的人/我是人的音乐喜欢。
音乐(我)喜欢。/我喜欢音乐。
I'm a person who[that] likes music.
I like music.

9. 我们它认识它。/它我们认识。follow the  original order, "know" has another meaning which is "知道"
We know it.

Aug. 20

Hello,here can be describe better.If you want to say are you coming back?better translate as你（正）在回来吗？If you want to say will you come back?better translate as 你（会）回来吗？because 你回来吗？means still not happen,just a "be+doing" may not very proper

5. 他们没有钱。
    他们没有了钱。<< pretty sure that's wrong..
    They have no money.
    They had no money.

他们没有钱。They don't have money.

他们没有了钱。They already don't have money.

6. 他是好老师。
He's a good teacher.

7. 他认识女孩的是大学生。
He knows a girl who's a college student.

他认识的一个女孩是大学生。

8. 我是人的喜欢音乐/我是人的音乐喜欢。
音乐(我)喜欢。/我喜欢音乐。
I'm a person who[that] likes music.
I like music.

我是一个喜欢音乐的人。

我喜欢音乐。

9. 我们它认识。
We know it.

我们认识它。

Hello,the expression I amended is that I try to help you translate like a native speaker,some sentences can't say that you are wrong,but my modify will makes you express more like a native speaker ,thanks.

Aug. 20