How much of our brain do we use?

[tufguy]

Joann: How much of our brain do we use?

John: We use about 10% of our brain. Just imagine what would happen if we started using 100% of our brain?

Joann: No, we use 100% of our brain every day. It is a myth that we use only 10% of our brain.

Could you please check my sentences?

 

[emsr2d2]

They're all grammatically correct. Note that "Joann" is an unlikely spelling of a name in English. It's more likely to be either Joanne or Joanna (or just Joan).

 

[GoesStation]

Just imagine what would happen if we started using 100% of our brain!

This is an exclamatory statement, not a question.