The court may submit to the jury, together with appropriate forms for a general verdict, written interrogatories upon one or more issues of fact the decision of which is necessary to a verdict. The court shall give such written instructions as may be necessary to enable the jury both to make answers to the interrogatories and to render a general verdict, and the court shall direct the jury both to make written answers and to render a general verdict. When the general verdict and the answers are harmonious, the court shall direct the entry of the appropriate judgment upon the verdict and answers. When the answers are consistent with each other but one or more is inconsistent with the general verdict, the court may direct the entry of judgment in accordance with the answers, notwithstanding the general verdict, or may return the jury for further consideration of its answers and verdict or may order a new trial. When the answers are inconsistent with each other and one or more is likewise inconsistent with the general verdict, the court shall not direct the entry of judgment but may return the jury for further consideration of its answers and verdict or may order a new trial.