1. fun
I was fun because I watched a comedy movie.

> I had fun because I watched a comedy movie.

2. need
I need to have a dinner.

> This sentence is correct or I need to eat dinner.

3. always
I always study math to do my homework.

> This sentence is correct or I always study Math to answer my homework.

4. before
Before class, I have a break time.

> It's my break time before this class.

5. Monday
On monday, I have a violine class.

> On Monday, I will have a violin class or Every Monday, I have a violin class.

6. meet

I meet my friend and I go to a library and watch a movie.

> I met my friend, then I  went to the library and watched a movie after.

or I will meet my friend then I will go  to the library and watch a movie after. 

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Hello there Eric!

    Please read and take note your corrections for this homework. Anyway, you made some sentences correctly. Keep up the good work! ^^

Just continue studying the Subject and Verb Agreement, as well as the  Tenses of the Verb. (PRESENT, PAST AND FUTURE)

Take care always and see you on Friday. ^^

~Teacher Cassie