How to make a backyard badminton court<br>Decide where to make your badminton court. If you have a small backyard, you don't have many options except putting it in the middle. But if you have a bigger space, you can put your badminton court anywhere.
Badminton courts can only be built in backyards
The context gives us no information about what badminton. While we know a court can be built in a backyard, we do not know for sure whether or not a court can be built elsewhere. The system may have presumed that a court can be built elsewhere, but this knowledge is outside of the context. 
( z1 possible :ARG1 ( z2 build :ARG1 ( z3 court :mod ( z4 badminton ) ) :location ( z5 backyard ) :mod ( z6 only ) ) )