What they taught you was wrong
As Will Rogers said, “It ain’t what you don’t know that hurts you. It’s what you know that ain’t so.”
We sometimes get complaints from our readers about things that are not wrong. Unfortunately, generations of English teachers have taught what H.W. Fowler termed “superstitions” or “fetishes” — “unintelligent applications of an unintelligent dogma.”
In Garner’s Modern American Usage, one of the most sensible and useful manuals on usage currently available, Bryan Garner presents his nominees for the top ten superstitions of English usage. Among them:
Never split an infinitive or a verb phrase (auxiliary form and main verb).
Never end a sentence with a preposition.
Never begin a sentence with “and” or “but.”
Never use “since” to mean “because.”
These and other shibboleths have been embedded in grammar books for a long time, and their origins, which you can find described in Merriam-Webster’s Dictionary of English Usage, are interesting. In the 18th century, when an emerging middle class was making money and coming into political power, it created a market for books on how to use English properly. The people who set the standards had, of course, been educated in Latin and Greek (English not having become a university subject until the end of the 19th century), and they thought that to be correct, English grammar had to follow the grammar of the classical languages. John Dryden, for example, saw that Latin sentences do not end with prepositions, and so he concluded that English sentences ought not.
English is complicated enough on its own. There’s no need to struggle over rules that are not really rules.