In Grammar check^x, Tenses^x

Okay this is a quick essay I wrote for English. I had to write how Gaston Leroux made the Phantom a likeable character. I had a bit of an issue writing on this and I know you can tell but the main thing I am worried about is the grammar and my tense usage. I have an issue with switching...

Hi Guru, I am very confused of how to use the "s" and the "ed". He, she and it eg he eats but how do you explain the difference between sport & sports. "ed" is a past tense how do you explain "as far as I'm concern or concerned and why. rgds