# Rules of Interpretation / Construction — Overview
Courts use established rules of interpretation (or construction) to determine the meaning of statutory provisions. These rules are grouped into Primary Rules and Secondary Rules.
## (A) Primary Rules
These are the principal rules that courts apply first:
1. Rule of Literal Construction — words are given their plain, ordinary meaning.
2. Rule of Reasonable Construction — words are interpreted in a sensible, rational manner.
3. Rule of Beneficial Construction (Heydon's / Mischief Rule) — the interpretation should suppress the mischief and advance the remedy.
4. Rule of Harmonious Construction — conflicting provisions must be reconciled so that all are given effect.
5. Rule of Exceptional Construction — used when normal rules produce absurd results.
6. Rule of Ejusdem Generis — general words following specific words take their colour from the specific words.
## (B) Secondary Rules
These are subsidiary or supporting rules:
1. Noscitur a Sociis — a word is known by the company it keeps.
2. Expressio Unius Est Exclusio Alterius — express mention of one thing implies the exclusion of another.
3. Contemporanea Expositio — contemporaneous exposition; meaning of a statute is best understood at the time it was enacted.
## Why the Distinction Matters
- Primary rules are the first port of call for the court — they govern the basic approach.
- Secondary rules are applied as supplementary aids when primary rules leave room for doubt.
## Quick Reference Table
| Type | Rules |
|---|---|
| Primary | Literal, Reasonable, Beneficial (Mischief), Harmonious, Exceptional, Ejusdem Generis |
| Secondary | Noscitur a Sociis, Expressio Unius Est Exclusio Alterius, Contemporanea Expositio |