7 grammar rules you really should pay attention to

7 grammar rules you really should pay attention to 

1. The subjunctive
This one is pretty simple. When you're writing about a non-true situation — usually following the word if or the verb wish — the verb to be is rendered as were.
2. Bad parallelism
This issue comes up most often in lists, for example: My friend made salsa, guacamole, and brought chips. If you start out by having made cover the first two items, it has to cover subsequent ones as well. To fix, you usually have to do just a little rewriting. Thus, My friend made salsa and guacamole and brought chips to go with them.
3. Verb problems
There are a few persistent troublemakers you should be aware of.
4. Pronoun problemsLet's take a look at three little words. Not "I love you," but me, myself and I. Grammatically, they can be called object, reflexive, and subject. As long as they're by themselves, object and subject don't give anyone problems.
5. The 'dangling' conversation
In a class, I once assigned students to "review" a consumer product. One student chose a bra sold by Victoria's Secret.
6. The semicolon
I sometimes say that when you feel like using a semicolon, lay lie down till the urge goes away. But if you just can't resist, remember that there are really only two proper uses for this piece of punctuation. One is to separate two complete clauses (a construction with a subject and verb that could stand on its own as a sentence).
7. WordsAs I noted in my previous article, the meaning of words inevitably and perennially change. And you can get in trouble when you use a meaning that has not yet been widely accepted. 
Webgraphy: https://theweek.com/article/index/241295/7-grammar-rules-you-really-should-pay-attention-to