Here are 24 common grammatical mistakes you want to avoid. Don't use no double negatives. Make each pronoun agree with their antecedent. Join clauses good, like a conjunction should. When dangling, watch your participles.
Verbs has to agree with their subjects.
Don't use commas, which aren't necessary. Try not to ever split infinitives. Its important to use your apostrophe's correctly. Don't write runon sentences they are hard to read. It behooves the writer to avoid archaic expressions.