OPINION OF THE COURT BY

In this appeal, the issue is whether plaintiffs-appellants’ suit is barred by the statute of limitations under § 657-8,1 Hawaii Revised Statutes. The circuit court dismissed plaintiffs-appellants’ com*81plaint, ruling that § 657-8 barred their claims. We disagree and reverse for reasons set forth herein.

Plaintiffs-appellants are homeowners (Homeowners). In 1977, they filed a complaint in the circuit court against Dan Ostrow Construction Co., Inc. (Contractor) and other unidentified defendants for damages based on both contract and tort claims. Their complaint alleges that in 1968, their homes were built by Contractor as part of a construction project; that the construction contract required Contractor to use corrosion-resistant nails; and that nine years later in 1977, shingles from the roofs of Homeowners’ houses began falling off, which led to the discovery that non-corrosion-resistant nails were used in constructing the roofs.

I.

HRS § 657-8 (1976 & Supp. 1980) prohibits any suit from being brought to recover damages for personal or property injury “arising out of any condition of an improvement to real property,” unless it is instituted not more than “two years after the cause of action has accrued, but in any case not more than six years after the completion of the improvement....”

This immunity provision means'that regardless of when, a cause of action accrues, an “outside” limitation of six years would bar any complaint from being filed more than six years after completion of the improvement. See Stand. Comm. Rep. No. 707-74, 7th Hawaii Leg., 2d Gen. Sess., reprinted in 1974 House Journal 822.2

*82It would therefore appear that Homeowners’ suit is barred by the outside limitation period of six years. The homes in question were completed in 1968 and suit was not filed until 1977, approximately nine years later. However, our attention is focused upon Section 2, Act 133, Session Laws of Hawaii 1972, which we hold governs the disposition of this appeal.

II.

Act 133, Session Laws of Hawaii 1972, amended HRS § 657-8 to lower the period after which suit would be barred from ten years to six years from the performance or furnishing of services.3 Accompanying this amendment was a “savings clause” in Section 2 of Act 133, which provided that “[t]his Act does not affect rights and duties that matured, penalties that were incurred, and proceedings begun, before its effective date.” (Emphasis supplied.)4 By this provision, the legislature manifested its intent to give the amended § 657-8 prospective effect only, without disturbing rights, duties, penalties and proceedings in effect before May 20, 1972. Consequently, Homeowners’ suit would not have been barred by the *83six-year limitation if they had rights that had matured prior to May 20, 1972. Instead, their action would be governed by the 1967 version of HRS § 657-8, and be allowed to proceed as having been brought within ten years of the furnishing and performance of services in question.

Contractor, however, argues that Homeowners’ claim accrued, more than six years after construction of their homes was completed and that the 1974 version of the statute operates to bar their claim. In oral argument, Contractor contended that the words “matured” and “accrued” appearing in § 657-8 have the same meaning. By this interpolation, Contractor is able to conclude that Homeowners had no matured rights because their injuries had not been discovered on or before May 29, 1974, and therefore that the bar of § 657-8 as amended in 1974 applies to their claim.

We disagree. At the outset, we note that the crucial savings clause in this case is that which appeared in 1972, as opposed to that which was added with the 1974 amendment, as Homeowners’ improvements were built and completed after the enactment of the original statute in 1967 but prior to the 1972 amendment.5 More importantly, however, we do not read the words “matured” and “accrued” to have the same meaning and legal effect. To reach our conclusion, we' are aided by several presumptions. Words or phrases used in two or more sections of a statute are presumed to be used in the same sense throughout, Rodrigues v. State, 52 Haw. 156, 472 P.2d 509 (1970), but by the same token, different words in a statute are presumed to have different meanings. Additionally, the legislature is presumed to know the law when enacting statutes, and we must presume that the legislature knew of the definition we assigned to the word “accrued” in Yoshizaki v. Hilo Hospital, 50 Haw. 150, 433 P.2d 220 (1967), at the time it amended § 657-8 in 1972.

In Yoshizaki, we defined the word “accrued” as it appears in Hawaii’s statutes of limitation to mean that the statute does not begin *84to run until the plaintiff knew or should have known of defendant’s negligence. Id. at 154, 433 P.2d at 223; see Waugh v. University of Hawaii, 63 Haw. 117, 621 P.2d 957 (1980); Basque v. Yuk Lin Liau, 50 Haw. 397, 441 P.2d 636 (1968). Thus, the rule of discovery controls the question of when the running of the limitation period is triggered.

*84If the legislature intended to ascribe to the 1972 savings clause the results of Yoshizaki, we must presume that it would have used “accrued” in place of “matured” therein.6 Not having done so, we conclude that a different meaning was intended. Being bound by the plain meaning of statutory language, see State v. Sylva, 61 Haw. 385, 388, 605 P.2d 496, 498 (1980); University of Hawaii v. Leahi Foundation, 56 Haw. 404, 407, 537 P.2d 1190, 1193 (1975), we conclude that § 657-8 would not bar Homeowners’ complaint if Homeowners had acquired any rights against Contractor prior to the effective date of the 1972 amendments, regardless of whether they had discovered or should have discovered the construction defect complained of at that time.

We hold that when Contractor committed the act complained of, his action was not free from legal consequences. On the contrary, Homeowners acquired a cause of action against Contractor for damages, except that, for reasons that are obvious, the cause of action by necessity remained dormant or inchoate. Nevertheless, from the date of Contractor’s misfeasance in 1968, Homeowners had a right to sue Contractor. It is this matured right that was not disturbed by subsequent amendments to § 657-8.

We conclude it was error for the trial court to dismiss Homeowners’ claim.

We need not reach the constitutional issue raised by Homeowners.

Reversed and remanded for action consistent herewith.

*85CONCURRING OPINION OF

I concur in the result reached by the majority.