Aids to Interpretation and Language Rules
Judges don't work in isolation – they've got loads of helpful tools called aids to interpretation. Internal aids are found within the statute itself: long titles, preambles, headings, schedules, and interpretation sections that define key terms.
External aids come from outside the statute and include dictionaries, official reports, international treaties, and the Interpretation Act 1978. Since Pepper v Hart (1993), judges can even use Hansard to see what ministers actually said during debates, but only under strict conditions.
The rules of language are brilliant shortcuts that help judges interpret unclear words. Ejusdem generis means general words take their meaning from specific words around them – so 'dogs, cats and other animals' would only include other domestic pets, not wild animals.
Expressio unius est exclusio works on the principle that mentioning specific things excludes everything else, whilst noscitur a sociis means words get their meaning from their neighbours in the sentence.
Pro Tip: These language rules might sound fancy in Latin, but they're just common-sense ways of working out what Parliament probably meant to say.