Student Use of the English Language

It is the end of the school year again, and as usual, I've about had it with the horrendous spelling and inability to properly use the English language. There are days when I am grading papers where I cannot read most of what has been written because penmanship is so terrible. There are some particular pet peeves of mine that I see every year with student use of the English language. Here is a list:
1. Sixty percent of my students misspell the word "separate" as "seperate". I correct this on their lab reports, homework and tests multiple times in the year, and a few learn, but most simply ignore it.
2. The phrase "could have" or "should have" or "might have" are written as "could of", "should of" and "might of". This makes no sense, but totally escapes the notice of my students, no matter how many times I correct this.
3. Can you tell why this one is irritating? "Dr. Mehigh, can I axe you somethin?"
4. Student writing: "There was alot of liquid in the beaker." "A lot" is two words.
5. Student lab report: "There weren't no equiptment in my drawer so I slept." (God help us all.)
6. Interchange one of these for any other no matter what is being written and you will understand why I have a headache after school. "Their, There, They're". The most frequent problem is to write "there" for "they're".
7. Mixing singulars and plurals. "The largest problems, which we all had, was that...".
8. The use of a general pronoun to describe a specific item. "It was hot, but they were not properly stored." What is "it"? What is "they"? I mark more answers wrong for this than any other reason.
9. "The cell swole up and became heightened". Cells do swell up, but they don't grow taller, they grow larger.
10. Interchange one of these for any other: "Two, to, too". "My lab partner got the same result to." To where? To what? Huh?
Some days I sit and dream about throwing all of the student papers I am grading into the trash, and picking up a nice novel. I wonder, do the students who routinely write and speak this way have parents guilty of the same? What have you noticed?

Prayers for Maria Garcia, senior OHS, who was in a bad car accident going home from the Monday night band concert. She was hit by a truck and broke her hip. She's pretty banged up and needed surgery today. I heard she is at St. John's but I am not certain. Poor kid won't even get to go to her own graduation.