I suspect you are a bit tired. When that happens, people often fall back to informal speaking, which is very poor grammar.
If you have something like Kaplan Premier
, run through an SC exercise, and keep 2 rules in mind:
1 - remember singular tenses; I am, they are, etc.
2 - parallel - if the first part of the sentence uses a style, the part which completes the sentence will use the same style. Don't leave anything hanging, and make sure the completion clearly refers to what the first part is saying.
I'm guessing that will show improvement. And between now and the test, watch less TV, and read more books. That alone will help you focus on better grammar.