Levels of Distractibility: Who cares? = *. Some people will be distracted from your meaning: = **. Many people will be distracted from your meaning: = ***.
Question: I've heard someone say that one of the worst crimes you can commit against English is to split infinitives. What is an infinitive and why is it wrong to split it?
Answer: "To" with a verb is called an infinitive: "to run," etc.
To put a word between the "to" and the verb is called a "split infinitive," cursed by many a grammar purist: "to better prepare...."
If the split infinitive sounds smooth, use it. Don't make an awkward construction in order to un-split the infinitive. When in doubt, write around it: Instead of "...to better prepare," "I can improve my preparation by...."
A matter of judgment.
Level of Distraction: (*). Everybody does it.