Old habits can be hard to break, but when it comes to grammar rules we need to stop the cycle somewhere. Grammar teachers, infamous for their stodgy rules, perpetuate a number of grammar myths.
Some of the wrong things your English teachers taught you are just outdated rules. Others are actually soft rules with plenty of exceptions. Find clarity regarding these grammar myths and you’ll enjoy confidently using language with the real rules in mind.
Some of us will downright enjoy breaking these incorrect “rules.”
Don't start a sentence with and, but, because, or however. We can likely all agree that many sentences sound less polished when beginning with one of these words. But we can also agree that it often makes sense. No absolute rule exists regarding this, so it’s up to the writer to use these sentence-starters sparingly. And make sure you have appropriate commas if using “however.”
Prepositions can’t end sentences. A British clergyman in the 1700's devised this old rule. Clearly there are sentences that naturally end with prepositions and would have to be forcefully overwrought to have it otherwise.
Never split an infinitive. The base form of any verb, as in “to write,” has been the subject of a myth that you cannot split the “to” and the verb itself. Balderdash. Insert adverbs as you see fit, so long as the meaning of the sentence remains clear.
The way you make words ending in “s” possessive is wrong. When words end in the letter “s” you can choose to use simply an apostrophe or an apostrophe and another “s.” Uniformity throughout your writing is the real rule. Just know that many people prefer the lone apostrophe for plurals.
Never use the word “gotten.” There’s nothing wrong with “have gotten” to mean “have acquired” in US English. The British stopped using it centuries ago, but America never did. On that note, it often helps to examine whether an old rule originates from British rather than American usage.