*203 Opinion
Plaintiffs Real and Shirley Morin (Morin) appeal an order denying their request for prejudgment interest under Civil Code section 3291 against defendants ABA Recovery Service, Inc., Richard Egley and Henry Rose. Morin contends section 3291 mandates an award of interest. Although we find section 329l’s language to be mandatory, on this record we are unable to determine whether Morin is entitled to an award of prejudgment interest. We thus reverse the order and remand the matter to the superior court for further proceedings.
I
In August 1980 Morin sued defendants for wrongfully repossessing Morin’s trailer, alleging causes of action for intentional infliction of emotional distress and possession of personal property. Morin sought compensatory damages according to proof and $15,000 punitive damages. In September 1980 defendants answered Morin’s complaint.
In December 1983 Morin served defendants with an offer to settle for $24,000 under Code of Civil Procedure section 998. Defendants allowed Morin’s offer to expire.
In March 1984 the matter was arbitrated. The arbitrator awarded Morin $75,000. Defendants rejected the arbitrator’s award and sought a trial de novo.
In June 1985 defendants offered Morin $40,000 under Code of Civil Procedure section 998. Morin did not accept defendants’ offer.
In September 1985 Morin filed an amended complaint for possession of personal property, intentional infliction of emotional distress, negligent infliction of emotional distress and negligence.
In September 1985 jury trial began. After Morin rested, defendants offered Morin $72,000 plus an additional $10,000 over time. Morin declined. The matter went to the jury. In November 1985 the court entered $67,500 judgment on general verdict favoring Morin, including $27,500 compensatory damages and $40,000 punitive damages.
Morin filed a cost memorandum seeking prejudgment interest under Civil Code section 3291. After hearing, the court denied Morin’s request for prejudgment interest. The court stated it believed it had "... discretion to *204 deny prejudgment interest otherwise awardable under CC 3291.” Morin appeals the order denying prejudgment interest.
II
Code of Civil Procedure section 998 provides in relevant part: “(a) The costs allowed under Sections 1031 and 1032 shall be withheld or augmented as provided in this section.
“(b) Not less than 10 days prior to commencement of trial, any party may serve an. offer in writing upon any other party to the action to allow judgment to be taken in accordance with the terms and conditions stated at that time.
“(1) If the offer is accepted, the offer with proof of acceptance shall be filed and the clerk or the judge shall enter judgment accordingly.
“(2) If the offer is not accepted prior to trial or within 30 days after it is made, whichever occurs first, it shall be deemed withdrawn, and cannot be given in evidence upon the trial.
“(d) If an offer made by a plaintiff is not accepted and the defendant fails to obtain a more favorable judgment, the court in its discretion may require the defendant to pay a reasonable sum to cover costs of the services of expert witnesses, who are not regular employees of any party, actually incurred and reasonably necessary in either, or both, the preparation or trial of the case by the plaintiff, in addition to plaintiff’s costs.”
Civil Code section 3291 provides in relevant part: “In any action brought to recover damages for personal injury sustained by any person resulting from or occasioned by the tort of any other person, corporation, association, or partnership, whether by negligence or by willful intent of the other person, corporation, association, or partnership, and whether the injury was fatal or otherwise, it is lawful for the plaintiff in the complaint to claim interest on the damages alleged as provided in this section.
“If the plaintiff makes an offer pursuant to Section 998 of the Code of Civil Procedure which the defendant does not accept prior to trial or within 30 days, whichever occurs first, and the plaintiff obtains a more favorable judgment, the judgment shall bear interest at the legal rate of 10 percent per annum calculated from the date of the plaintiff’s first offer pursuant to *205 Section 998 of the Code of Civil Procedure which is exceeded by the judgment, and interest shall accrue until the satisfaction of judgment.”
Ill
Morin contends the court erred in denying prejudgment interest, asserting Civil Code section 3291 mandated an award of such interest here.
“ ‘The fundamental rule of statutory construction is that the court should ascertain the intent of the Legislature so as to effectuate the purpose of the law.’
(Select Base Materials
v.
Board of Equal.,
On its face Civil Code section 3291 appears to impose upon the court a mandatory obligation to award prejudgment interest where the statutory conditions are met. The words of the statute providing the judgment “shall” bear 10 percent prejudgment interest are reasonably clear. Generally the word “shall” connotes a mandatory obligation. “The word ‘shall’ is ordinarily ‘used in laws, regulations, or directives to express what is mandatory.’ [Citations.] ‘May,’ on the other hand, is usually permissive.” (Ho
gya
v.
Superior Court, supra,
However, as defendants correctly note, a statute’s use of the word “shall” does not always mean its provisions are mandatory. “Shall” has
*206
sometimes been judicially construed as directory or permissive.
(Governing Board
v.
Felt
(1976)
“‘The test is this: “If to construe it as directory would render it ineffective and meaningless it should not receive that construction.” [Citations.] Thus, a statute was held to be mandatory where “to construe this provision of the section as directory merely would be to defeat the very purpose of its enactment.” [Citation.] “. . . [I]t appears that if public policy is in favor of the imperative meaning, the words referred to will be held mandatory.” [Citation.] “In construing a statute matters of substance are to be construed as mandatory.” [Citation.]’ ”
(Hogya
v.
Superior Court, supra,
Defendants contend the Legislature could not have intended to allow prejudgment interest under Civil Code section 3291 where the plaintiff’s conduct during settlement negotiations was unreasonable, inequitable or in bad faith. However, defendants point to nothing in section 329 l’s legislative history suggesting the Legislature intended an award of prejudgment interest to be merely discretionary. On the contrary, the available legislative history leads to the conclusion the statute’s language is, indeed, mandatory. The manifest purpose of section 3291 is to encourage settlement. (Ops. Cal. Legis. Counsel, No. 17984 (Nov. 2, 1982) Judgment and Prejudgment Interest; accord,
Woodard
v.
Southern Cal. Permanente Medical Group
(1985)
*207
Construing Civil Code section 3291 as mandating prejudgment interest is consistent with dictum in
Woodard
v.
Southern Cal. Permanente Medical Group, supra,
Finally, defendants contend Civil Code section 3291 should be construed as granting the trial court discretion to deny prejudgment interest because Code of Civil Procedure section 998 allows only a discretionary cost award to plaintiffs under the same circumstances. However, the Legislature clearly stated in Code of Civil Procedure section 998 the court “may” award costs while stating in Civil Code section 3291 the judgment “shall” bear prejudgment interest. Defendants identify no legal requirement the Legislature treat costs and prejudgment interest identically. Further, “[w]hen the Legislature has, as here, used both ‘shall’ and ‘may’ in close proximity in a particular context, we may fairly infer the Legislature intended mandatory and discretionary meanings, respectively.”
(In re Richard E.
(1978)
Thus, we hold where the statutory conditions are met, Civil Code section 3291 mandates an award of prejudgment interest.
IV
Defendants contend Civil Code section 3291 does not authorize a prejudgment interest award where, as here, damages may be based upon claims *208 other than those for personal injury. Defendants thus assert even if section 329l’s language is mandatory, the order denying prejudgment interest here should be affirmed.
We read Civil Code section 3291 as authorizing prejudgment interest only for the personal injury portion of a more general total recovery. We hold establishing the threshold proposition that a certain award is in fact for personal injury is a burden properly borne by the party seeking an award of interest. As we explain below, we believe the most efficient means of meeting that burden is through special jury findings. However, since such findings are not the sole means by which the fact and amount of personal injury recovery may be established, and the trial court did not reach the issue, we remand for further proceedings.
Morin’s first amended complaint asserted causes of action for possession of personal property, intentional infliction of emotional distress, negligent infliction of emotional distress and negligence. In addition to seeking personal injury damages for emotional distress, Morin’s pleading sought damages for wrongful repossession and detention of personal property including loss of use and enjoyment, expenses for alternative living quarters, replacement items of personal property and lost wages. The record does not show either party asked the court for special jury findings itemizing damages awarded. The jury rendered a general verdict favoring Morin for $27,500 general damages and $40,000 punitive damages. Opposing Morin’s request for prejudgment interest, defendants argued no prejudgment interest should be awarded because the verdict did not indicate how much was awarded for personal injury. The superior court did not reach the issue because it misconstrued Civil Code section 329l’s language as discretionary.
Civil Code section 3291 authorizes an award of prejudgment interest only for damages for personal injury. Morin sought personal injury damages and other damages. The jury returned a general verdict favoring Morin. We are unable to discern the basis for the jury’s damage award. The jury may have awarded its verdict to Morin on the basis of claims for other than personal injury damages. On this record it is impossible to determine if any portion of the jury award reflects personal injury damages and thus if Morin is entitled to prejudgment interest under section 3291.
Under similar circumstances, attorney fees under Civil Code section 1717 have been limited or denied.
(McKenzie
v.
Kaiser-Aetna
(1976)
In
McKenzie
v.
Kaiser-Aetna, supra,
In affirming the trial judge’s denial of the plaintiff’s request for attorney fees, the appellate court in McKenzie v. Kaiser-Aetna, supra, 55 Cal.App.3d at pages 88-89, stated: “The net verdict and judgment were in appellant’s [plaintiff’s] favor, but there is no way to ascertain, in the absence of special jury findings, on which of the theories of recovery (breach of contract, negligent misrepresentation, or breach of implied warranty) the jury mainly based its award to appellant. Those theories do not all call for identical determinations of fact .... The three theories of recovery were thus not merely the same cause of action under different guises. . . . [fi] [A]n action for negligent misrepresentation is not an action to enforce the provisions of a contract. As the jury may have awarded its verdict to appellant on the basis of the negligent misrepresentation theory, appellant cannot recover attorney’s fees under section 1717.”
Like the plaintiff in
McKenzie
v.
Kaiser-Aetna, supra,
Imposing on Morin the burden to prove entitlement to prejudgment interest under Civil Code section 3291 is consistent with the statute’s language and California law regarding burden of proof. Section 3291 autho *210 rizes the plaintiff in an action to recover damages for personal injury to claim in his complaint interest on the damages alleged. “The basic rule, followed in California and elsewhere, is that whatever facts a party must affirmatively plead, he also has the burden of proving.” (1 Witkin, Cal. Evidence (3d ed. 1986) Burden of Proof and Presumptions, § 131, p. 116.) Under Evidence Code section 500, a party generally “ . . . has the burden of proof as to each fact the existence or nonexistence of which is essential to the claim for relief or defense that he is asserting.”
Morin contends defendants as losing parties had the burden to request special verdicts because the general verdict imported a finding in his favor on the personal injury claims. Morin’s contention is based upon the principle stated in a line of cases discussing issues regarding substantial evidence.
(McCloud
v.
Roy Riegels Chemicals
(1971)
*211
Imperial Cattle Co.
v.
Imperial Irrigation Dist.
(1985)
Unlike the plaintiff in
McKenzie
v.
Kaiser-Aetna, supra, 55
Cal.App.3d 84, the plaintiff in
Imperial Cattle Co.
v.
Imperial Irrigation Dist., supra,
Like the plaintiff in
McKenzie
v.
Kaiser-Aetna, supra,
The order denying Morin prejudgment interest must be reversed and the matter remanded for the trial court to determine the portion, if any, of the verdict attributable to personal injury claims and award prejudgment interest accordingly. If the trial court is unable to make such determination, prejudgment interest shall be denied.
Disposition
The order denying prejudgment interest is reversed. The matter is remanded to the superior court for further proceedings in harmony with this opinion. Each side to bear its own costs on appeal.
Wiener, J., and Work, J., concurred.
Notes
We acknowledge concern the mandatory interest award required by Civil Code section 3291 may work unfairly where the plaintiff has rejected the defendant’s written offer to settle for a sum ultimately exceeding the jury verdict. Treating the statute as requiring an interest award in any case where the judgment exceeds the plaintiff’s rejected offer will result in inequity to a defendant making a timely good faith offer to settle for an amount in fact exceeding the later jury award. We nonetheless believe the Legislature rejected this concern. The Legislature intended different treatment of personal injury actions because of the manifest greater prejudice of delay in recovering personal injury damages as compared to contractual or busi *207 ness-tort losses given the probability personal injury plaintiffs are likely to be physically as well as monetarily impaired. We leave to the Legislature any change in the statute.
Greenfield finds support in legislative history suggesting the Legislature intended Civil Code section 3291 to apply to punitive damage awards. The Legislature rejected a proposed amendment providing prejudgment interest would not accrue to any portion of the judgment representing punitive damages. (Sen. No. 203, Proposed Amendments (Aug. 31, 1981) 16 Assem. Final Hist. (1981-1982 Reg. Sess.) pp. 111, 116.)
