What is the tone of on letter writing

Jackson is a very smart little boy he can count to twenty and is only two years old. complete, run on sentence or comma splice

Awell-written summary should be used o in place of reading an original text to you review something that you have already read

What else do you think experts can learn from studying the language of written work? what do you think is the value of studying the language of william shakespeare whose writing is over hundreds of years old?