America is the land of invention. Every teacher of composition in the U.S. is a demon for spotting the comma splice, which is simply separating two complete clauses with a comma. As in
Mary had a little lamb, its fleece was white as snow.
In high schools, universities and colleges around the United States, teachers of composition are quick to circle that comma after “lamb” (it’s easy!) and jot C.S. in the margin. If, however, you were to submit a “sentence” like the above at Oxford or Cambridge, no Don would bat an eye. The feared comma splice is not really a matter of grammar; it’s just punctuation, which is meant to clarify, not define, the grammar (semantic and syntactic elements) of a sentence.
But take the final line of our little rhyme:
And everywhere that Mary went, the lamb was sure to go.
In all places where English composition is taught, the punctuation in this sentence would be judged “correct.” Why? Because “everywhere that Mary went” is an element modifying the competed action of “the lamb was sure to go.” (Note that this last “Because…” clause is not a complete sentence, but is, in my way of thinking, a perfectly clear and grammatically correct construction.)
Read a book by a Brit and you will see lots of comma splices. In most cases, an American author (having felt the lash of the C.S) will either insert the mysterious semicolon or use the more Hemingwayesque period.
My recommendation is that you be true to your school. I don’t write sentences that contain comma splices, out of habit more than punctiliousness.