I want to know if my sentences is grammatically correct or not.

[alex_genius_20]

I have made a dialogue:

My teacher: "Why did you write that on the board?"

Me: "1. I want to know if my sentences is grammatically correct."
Me: "2. I want to know if my sentence is grammatically correct or not."
Me: "3. I want to know whether my sentences is grammatically correct."
Me: "4. I want to know whether my sentence is grammatically correct or not."
Me: "5. I want to know whether or not my sentence is correct."

Hello,
I have some doubts on the blue sentences written by me. Would you please help me on them? Which ones are incorrect?

 

[emsr2d2]

For a start, all of your suggestions with "my sentences is" are incorrect. You have followed a plural noun with a singular verb.

 

[alex_genius_20]

Thanks for answering. Yes I have made a mistake there. What if I write them in singular form?

My teacher: "Why did you write that on the board?"

Me: "1. I want to know if my sentence is grammatically correct."
Me: "2. I want to know if my sentence is grammatically correct or not."
Me: "3. I want to know whether my sentence is grammatically correct."
Me: "4. I want to know whether my sentence is grammatically correct or not."
Me: "5. I want to know whether or not my sentence is correct."

 

[emsr2d2]

Thanks for answering. Yes I have made a mistake there. What if I write them in singular form?

My teacher: "Why did you write that on the board?"

Me: "1. I want to know if my sentence is grammatically correct."
Me: "2. I want to know if my sentence is grammatically correct or not."
Me: "3. I want to know whether my sentence is grammatically correct."
Me: "4. I want to know whether my sentence is grammatically correct or not."
Me: "5. I want to know whether or not my sentence is correct."

They're all acceptable.