Under CCP 2023.010 and 2023.030, providing evasive or false discovery responses is a discovery abuse for which the court must grant the opposing party monetary sanctions unless it finds there was substantial justification for the discovery abuse or awarding sanctions would be unjust. Here, the trial court found substantial abuse of discovery in providing false responses, but erroneously failed to award the opposing party monetary sanctions. The false responses were not substantially justified–i.e., well-grounded in law and fact. It would not be unjust to award sanctions as the erring party had substantial assets. Also, denial of monetary sanctions was not proper if based on the fact that the trial court issued other (terminating) sanctions under its inherent authority. However, the trial court did not abuse its discretion in denying sanctions against the erring party’s attorneys as there was substantial evidence (from the attorneys’ declarations) showing that the attorneys had not advised the erring party to engage in its discovery abuses.