10.3. Spelling
As a general rule the first entry in the Concise Oxford dictionary should be followed. An exception to this rule is the spelling of words ending in -ise/-ize. Although both forms are correct, the preferred spelling is ‘-ise’ and this should be applied to ensure consistency.
When adding -able, drop a final silent -e (debatable, conceivable) unless it affects a preceding consonant (changeable, traceable); the only common exceptions are sizeable and saleable (sizable, salable are US).
Use -ct- not -x- in connection, reflection, etc. Note also: carcass (plural: carcasses), not carcase/carcases.
10.3.1. Tricky plurals
Follow the list below:
| Singular | Plural |
| addendum | addenda |
| appendix | appendices |
| bacterium | bacteria |
| consortium | consortia |
| corrigendum | corrigenda |
| criterion | criteria |
| datum | data (takes plural verb) |
| focus | focuses (focal points) foci (mathematics) |
| formula | formulas (politics) formulae (science) |
| forum | forums (avoid fora) |
| index | indexes (books) indices (science, economics) |
| maximum | maximums maxima (science) |
| medium | mediums (life sciences, art) media (press, communications) |
| memorandum | memoranda |
| microfiche | microfiche (technically same as singular) |
| phenomenon | phenomena |
| plus | pluses |
| premium | premiums |
| referendum | referendums |
| spectrum | spectrums (politics) spectra (science) |
| surplus | surpluses |
| symposium | symposia |
| vortex | vortices |
10.3.2. Interference effects
Confusion between English words
Check typescripts for errors involving the words below:
| dependent (adj.) | dependant (noun) also: independent, dependence, dependency |
| license (verb) | licence (noun) |
| maintain (verb) | maintenance (noun) |
| premiss, premisses (propositions) | premises (building) |
| practise (verb) | practice (noun) |
| principal (adj./noun) | principle (noun only) |
Confusion between English and French
| English | French |
| address | adresse |
| apartment | appartement |
| competitiveness | compétitivité |
| correspondence | correspondance |
| defence | défense |
| environment | environnement |
| example | exemple |
| existent | existant |
| independence | indépendance |
| medicine | médecine |
| messenger | messager |
| negligible | négligeable |
| negotiation | négociation |
| offence | offense |
| recommendation | recommandation |
| reflection | réflexion |
| responsible | responsable |
| tariff | tarif |
