YOU ARE NOT YOUR OWN

I have had to write many papers in seminary. Research papers, book reports, reaction papers, decision summaries, on and on and... We're talking millions of papers, at least it feels that way. Looking back I've learned a ton having to write so much and so often. I've come to terms with the fact that I am a poor grammatical wizard and I should have listened to my English teachers in High School rather than a dozen other things I did that wasted time.

One of my professors posted a list of common errors made when writing papers. I must say I'm not near as bad as I used to be but I still blow it from time to time.

COMMON MISTAKES WHEN WRITING...
1) Write a sentence fragment. (Because it is right.)
2) Split an infinitive. (to further clarify)
3) Use a contraction. (it's, can't, won't, wouldn't, he's)
4) Use an apostrophe for the plural. (David then sent the soldier's into battle.)
5) Use verb tenses inconsistently. (The author writes well. He wrote his book last year.)
6) Cause a subject and verb to disagree. (A subject do like to agree with the verb.)
7) Misspell a word as a homophone. (their for there; precede for proceed, etc.)
8) Use the first or second person or other such designation. (I, you, we, the author)

What about you? Did you get all "A"s in English? Is this second nature for you? Or are you like me and end way too many sentences with prepositions?