I have more houses than you.
I have more houses than yours.
Which one is right? Can you please explain why?
I have more houses than you.
I have more houses than yours.
Which one is right? Can you please explain why?
"I have more houses than you" can be regarded as a shortened form of the two-clause sentence "I have more houses than you have houses".
For reasons of brevity, the repetition is removed, and this happens almost always: nobody speaks with that much unnecessary repetition. Speakers perform this elision and expect it from others.
The shortened form is not possible when different objects are being compared, for instance:
I have more reasons to dislike that man than a dog has fleas.
This says that the number of reasons I have for disliking that man is greater than the number of fleas on a dog. ("... Than a dog has fleas" is a common expression: research it!)
This elided-two-clause hypothesis explains why the correct sentence is the one with "you", rather than "yours", since:
I have more houses than {you | yours*} have houses.
"Yours" cannot be correct here in any way.
Whenever it looks like "yours" is used as a noun, such as the subject of a clause, there is some word that is being elided. For instance:
My shoes are dirty; yours aren't. ["My shoes are dirty; your shoes aren't dirty." the words "dirty" and "shoes" disappear; "shoes" is absorbed into "your", producing "yours".]
In the sentence "I have more houses than yours*" we cannot identify any anything that is yours. There is no "your [something]" that "yours" can possibly stand for.
On the other hand:
My relatives have more houses than yours.
Aha, this is now correct because "yours" can be readily identified as standing for "your relatives", and so the sentence means "my relatives have more houses than your relatives have houses".
Either sentence can be grammatically correct, depending on context. But the first form is probably what you want:
I have more houses than you.
This means that I have some number of houses, and you have some number of houses, and the number of houses I have is greater than the number you have.
I have more houses than yours.
This sentence is not valid on its own, but as a fragment it could be correct when taken in a larger context. For instance:
Person A: My boss has three houses!
Person B: My boss has eight houses. I have five houses. I have fewer houses than my boss, but I have more houses than yours!
Other examples, suggested by @EdwinAshworth:
Painter: I have more houses than yours to paint this summer.
Or...
Landlord: I'm making quite a bit of money; I have more houses than yours.