soweli tomo jan ➜ soweli tomo pi jan ante [?]

soweli tomo pi jan ante = someone else's dog

New sentence? [?]

No. As a matter of fact, I thought that the expression "soweli tomo jan" meant something like "human dog", and not "someone's dog". [?]

How would you translate "someone else's dog"? (I would still say "soweli tomo pi jan ante".)

Sonja's official Toki Pona book has the adjective "jan" as "someone's" (or "somebody's") and not "human", here:

mi weka e ike jan, la mi weka e ike mi.
If I erase somebody's faults, I cleanse myself of negativity.

It looks like "jan" as an adjective behaves like "mi", "sina" and "ona".

soweli tomo mi - my pet
soweli tomo sina - your pet
soweli tomo ona - their pet
soweli tomo jan - somebody's pet

So I think "somebody's pet" is a plausible read.

You're right. I hadn't noticed that use of the adjective "jan". Thanks a lot.

@Tepan

I'm thinking. Could I say this: soweli jan li kama weka tan tomo ona. [?]

I think that's a good sentence. I would translate it as "somebody's animal escaped from its home." But, good catch: when "tomo" is already in the context, then "soweli tomo" can be simply "soweli", I think.

I think such a sentence would be a different sentence, though. Currently, the dog may have disappeared during a family vacation while the family was making a break at the side of the road.

pona!