Nice question, Era. That’s actually a common grammar myth, which is the supposed prohibition of the “split-infinitive”. In reality, there is no such rule, so if you watch the international news report on TV, the anchor will use the split and non-split infinitives equally. Era, since you’re a non-native speaker, it wouldn’t hurt for you to avoid the so-called split infinitive, but just keep in mind that educated native speakers use both forms all the time and the “rule” is absolute nonsense. That being said, note that there is a famous Shakespeare line, "to be or not to be" — please don't change it ;)