I’ve been asked the same question twice within a week, so here I am, happy to clear up a misconception.
Question: Isn’t it unacceptable to start a sentence with the word because? I learned it was wrong.
Short answer: It is acceptable to start a sentence with any word you want.
Longer answer: Yes, it’s perfectly fine to start sentences with because. In fact, it’s a good idea when you want to vary sentence structures, create transitions, and write smoothly.
You have been a valued customer for seven years, and we are very grateful for your business. Because we appreciate our relationship with you, I want to personally explain a change in our delivery policy.
The clause beginning with because ties the idea in the first sentence to the idea in the second sentence. Beyond that, the two longish sentences (one compound, one complex) flow rather than sounding staccato. The because clause improves the flow.
Apparently, the silly rule against because beginning a sentence is an attempt by teachers to discourage young students from writing fragments:
I don’t have my homework. Because it blew out of my notebook.
The because question reminds me of a lyric in The Wizard of Oz, which I have written incorrectly as a fragment:
We’re off to see the wizard, the wonderful wizard of oz. Because, because, because, because, because–because of the wonderful things he does.
That’s exactly the thing teachers are trying to stamp out.
If you have been hesitant to start a sentence with because, forget that misguided rule. It’s perfectly okay.