Yeah. The major thing i have to work on is my grammar skills. My tutor emphasized heavily that i need to proofread my work. I did do it but not well enough. Silly mistakes like writing 'cast' instead of 'casts'. Also referencing! I learnt that you never put the first initial of the author you are referencing.
Yes, spelling and grammar is important. I find it helps to read your work out loud and that way you can tell when things sound off in a much easier way than when just reading the words.
The library has referencing guides online which are very useful.
Spelling and grammar and referencing often make up 5-15% of the mark so you have a lot of potential to get HD's if you sort these issues out.