Let p : It is raining.
q : We will go.
r : We play football.
Then,
The symbolic form of the given statement is p → (q ∧ r).
Since ~[p → (q ∧ r)] ≡ p ∧ ~(q ∧ r) ≡ p ∧ (q ∨ ~r),
The negation of the given statement is :
‘It is raining and we will not go or not play football.’