Or are they all acceptable?
He travels around the UK a lot. One week he'll be down in London. The next he'll be in Edinburgh.
He travels around the UK a lot. One week he'll be down in London, the next he'll be in Edinburgh.
He travels around the UK a lot. One week he'll be down in London; the next he'll be in Edinburgh.
Likewise, if I wanted to omit some words:
He travels around the UK a lot. One week he'll be down in London, the next in Edinburgh.
He travels around the UK a lot. One week he'll be down in London; the next, in Edinburgh.
He travels around the UK a lot. One week he'll be down in London, and the next, in Edinburgh. You could join the clauses with a comma in a sort of asyndeton, but the comma looks a bit fragile there all by itself, and it quacks like a splice, so throw in the "and" that is understood, anyway.
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He travels around the UK a lot. One week he'll be down in London, and the next, in Edinburgh.
You could join the clauses with a comma in a sort of asyndeton, but the comma looks a bit fragile there all by itself, and it quacks like a splice, so throw in the "and" that is understood, anyway. A full stop kills the flow. The semicolon smells of the lamp, and it kills the possibility of the