Not everyone agrees that infinitive verbs should be split, but there is no rule saying that we can't. It happens all the time!
A split infinitive is a full infinitive, such as to go, to run, to laugh, or to walk, with an adverb between both parts (to + adverb + verb). Examples of adverbs are happily, sleepily, dryly, and hungrily.
The most famous example of a split infinitive is from Star Trek: "To boldly go where no one has gone before."
Other examples include:
"It's important to always wash your hands before eating."
"We need to really try to win the game."
"He expects to completely fail the test."
"You should learn to not start fights with your sister."
Split Infinitives Grammar Quiz
Split Infinitives Lessons: