The Star Trek mission statement—“to boldly go where no one has gone before”—has been criticized many times by grammarians who insist that it’s wrong because inserting the adverb “boldly” between “to” and “go” yields a so-called “split infinitive.”
What’s an infinitive? It’s the absolute version of a verb—the ideal or idealized form. Another way to think of an infinitive is that it’s the name of a verb. Legend has it that the split infinitive phobia arose among academics schooled in Latin. The problem with obsessing over split infinitives is that English doesn’t have real infinitives the way other languages do—such as the French marcher (to walk) or the Spanish bebir (to drink). In English, infinitives are formed by preceding the root verb with the preposition to, as in to go, to eat, to talk, to run, etc. While Captain Picard of the Starship Enterprise might have been more correct to state “to go boldly where no one has gone before,” it might not have the same dramatic impact. The scriptwriters for Star Trek were probably well aware of how they were structuring Captain Picard’s bold statement.
Don’t worry about split infinitives because every native speaker of English splits them all the time. Dealing with a victim of a construction site accident, an emergency room physician might say to his patient, “This may hurt. I want to gently and carefully remove the nail embedded in your foot.” That’s the normal way this might be expressed. Were the physician grammar obsessed, he might say instead “I want to remove the nail in your foot gently and carefully.” The problem with this construction is that the adverbs gently and carefully are some distance from remove, the verb they are intended to modify. It also sounds a tad stilted. A good rule of thumb is not to worry much about splitting infinitives, but to try to keep the intervening verbiage as short as possible. “To boldly go” will fly, but “to energetically and with great determination go where no one has gone before” probably won’t.
Old-school grammarians are also adamant that a properly constructed English sentence should never end with a preposition. By their standards, “That’s something I never heard of“ is wrong and “That’s something of which I never heard” is correct.
Which sounds right to you? What do people normally say? The rule against ending with prepositions flies in the face of common English usage. In fact, this prohibition is belied by most of our ordinary imperatives: go in, go out, drive by, come over. Ultimately the only factor that determines what is correct is common acceptance. Trust your ears. You’re writing for an audience of intelligent readers, not for a handful of stuffy academics. Ninety-nine percent of readers will find nothing wrong with “That’s something I’d like to learn more about.”