Negation is the easy one:
The glass is always half full.
Conditional is when one statement depends on the other:
If it is a glass, then it is not always half full.
(I think something like that maybe.)
Conjunction is when you connect two statements together with an OR:
It is a glass OR it not always half full.
(Not sure on this one, sorry).
Disjunction is when you connect two statements together with an AND:
It is a glass AND it is not always half full.
(Again, sorry, not sure if this is exactly what they're looking for.)
