Consider the statement "The match will be played only if the...

Let $p:$ weather is good
and $q:$ ground is not wet

Given statement "The match will be played only if the weather is good and ground is not wet" can be written as $\left(p ∧ q\right)$

Now, negation of $p ∧ q$ is $~ \left(p ∧ q\right) ≡ ~ p ∨ ~ q$

which is equivalent to "The match will be played and weather is not good or ground is wet".