perfect and simple

Which would you use here and why? What are the factors which would lead you to "choose" one over the other?

[i]He's caught a cold and can't come to work.
He caught a cold and can't come to work.[/i]

Either of them, but usually the second because it's shorter, LOL.

I suspect that in British English (or at least in the 'standard' variety) the first one would be more natural.

When you are speaking to Americans you should use the simple past, but when you are speaking Britishers the simple past should be avoided and use the present perfect instead. This is how I learned it in the school.

Well Hans, what you learned in school about the pondian differences with respect to the simple past and the present perfect is mostly wrong.

At least if you put it the way you did.

The set of rules and habits concerning the use of such tenses in the US and UK is much more complex.

Your assessement is a major oversimplification.

Best,

Achab

"He caught a cold and _couldn't_ come to work" sounds better.

American English is a simplified form of English+slang which is far easier to learn than standard English which is studied throughout Europe.

I would go for past perfect as it emphasizes the current state. Simple past suggests a completed action, as in "He caught a cold and got over it, but for some reason he's still not coming to work."

And American English is not "slang". By many measures, American English is the standard and British is simplified, slang version of it. For instance, you've apparently adopted a simplified version of English that doesn't have commas.