Where p and q are statements, "p and q" is false if p is false.
Always
Sometimes
Never
If p or q is false, then p and q is false.
Always.
The expression "p and q" is false if and only if both p and q are false.
To determine if "p and q" is false, you would first need to evaluate the truth values of p and q. If either p or q (or both) are false, then the expression "p and q" will be false.
Therefore, "p and q" is false sometimes, when either p or q is false.