Although you're not taking  an English course per se, and you will never be specifically penalized for poor writing in and of itself, good writing and clear thinking are your friends. Don't let poor mechanics get in the way of your conceptual elegance. In order to aid you in that endeavor, I have appended the following hints.

Part 1

1) Avoid run-on sentences they are hard to read.

2) Don't use no double negatives.

3) Use the semi-colon properly, always use it where it is appropriate; and never where it isn't.

4) Do not put statements in the negative form.

5) The passive voice should be avoided by you at all times.

6) Verbs has to agree with their subjects.

7) No sentence fragments.

8) Proofread carefully to see if you any words out.

9) Avoid commas, that are not necessary.

10) A writer must not shift your point of view.

11) And don't start a sentence with a conjunction.

12) Place pronouns as close as possible, especially in long sentences, as of ten or more words, to their antecedents.

13) 1 should write out small numbers in words.

14) Writing carefully, dangling participles must be avoided.

15) If any word is improper at the end of a sentence, a linking verb is.

16) Steer clear of incorrect forms that have snuck into the language.

17) Avoid trendy words, even if they sound sweet or totally sick.

18) Take the bull by the hand and avoid mixed metaphors.

19) Never, ever use repetitive redundancies.

20) If you've been told once, you've been told a million times - resist hyperbole!

21) Try not to ever split infinitives.

22) Avoid clichés like the plague.

Part 2: Here's a further reason NOT to rely on spell check:

"Eye halve a spelling chequer

It came with my pea sea

It plainly marques for my revue

Miss steaks eye kin knot sea.

Eye strike a cay and type a word

And weight for it two say

Weather eye am wrong oar write

It shows me strait aweigh.

As soon as a mist ache is maid

It nose bee four two long

And eye can put the error rite

Its rare lea ever wrong.

Eye have run this poem threw it

I am shore your pleased two no

Its letter perfect awl the weigh

My chequer tolled me sew."