In English, an infinitive verb fufills the function of a noun and is formed with "to" -- thus, "to take," "to laugh," and "to be."
Many writers feel that it is bad style to "split an infinitive" by inserting a modifying word after the "to." The following are examples of split infinitives: "to greedily take," "to enthusiastically laugh," "to finally be."
|...to boldly go where no man has gone before.|
|...boldly to go (or to go boldly) where no man has gone before.|
Although the influential New Oxford Dictionary of English recently admitted that "in standard English the principle of allowing split infinitives is broadly accepted as both normal and useful" (August, 1998), there are nevertheless plenty of people who consider it unacceptable.
It's best never to split infinitives (unless you want to really emphasize something).
More on split infinitives.