Your spelling is bad. You do not have to write an essay on. I think you should open a dictionary if you are unsure about how to write before you start writing.
Your spelling is not good, you make a mistake it was to write the essay. I think you should open a dictionary if you are not sure about the terminology that is written before the writes.
the spelling of you are not well, you made a mistake when writing essays, I really think that you should be on dictionary if you are not sure about a word written before you begin to write.