$HCOOH$ is a weak acid. Conjugate base: $HCOO^-$, which is a weak base.
Work Step by Step
$HCOOH(aq) + H_2O(l) --> HCOO^-(aq) + H_3O^+(aq)$ As we can observe, $HCOO^-$ is the conjugate base of $HCOOH$. Since $HCOOH$ is a weak acid, his conjugate base will be weak too.