More complex word endings

Many complex words are derived from simple nouns and verbs through the addition of variable endings (known as ‘derivational suffixes’):

admire [verb]     admirable [adjective]     admiration [noun]

The spelling of complex words often follows general spelling rules, but these can be inconsistently applied, especially in newly formed words. This section covers the Australian spelling conventions for the following word endings:


When the suffix -able is added to a verb that ends in -e, the e is usually dropped. Spellings that retain the e are also around, but the simpler forms without the e are recommended:

livable     lovable     usable     movable     saleable     tradeable

The -eable form is more common in newly formed words (eg saleable, tradeable). When the verb ends in -ce or -ge (eg enhanceable, changeable), the e is retained to show that the c or g is pronounced as a ‘soft’ consonant (ie the c is pronounced as an s, and the g is pronounced as a j).

See also -ible/-able.

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Some verbs can be ended with -ed or -t: burn, dream, kneel, lean, leap, learn, smell, spell, spill and spoil. The -ed is generally used for the past tense and -t for the past participle or adjective:

The fire burned through 100 hectares of bush.     The toast was burnt to a crisp.

His heavy speech spoiled the tone of the event.     She behaved like a spoilt child.

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The plural spelling of nouns ending in -f is currently changing. A few that in the past took -ve have reverted to -f – for example, dwarfs (not dwarves) and scarfs (not scarves). Those that vary as plural nouns maintain the -f when used as verb:

hoofs/hooves     hoofed    

roofs/rooves     roofed

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The -ian ending is used for most adjectives derived from proper nouns, especially those formed in modern English:

Bostonian     Brazilian     Darwinian     Devonian     Freudian     Newtonian     Wagnerian

The same goes for adjectives derived from other nouns:

avian     grammarian     guardian     mammalian     reptilian

The -ean ending appears in words formed from classical names with e in the final syllable:

epicurean     European     Herculean     Procrustean     Promethean

A very few words can be spelled either way:

caesarean/caesarian     Argentinian/Argentinean

Note: Either spelling can be used if referring to Caesar, the Roman emperor, but caesarean is the preferred spelling throughout the world for a surgical birth.

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The suffixes -ible and -able are used with many adjectives in English. Words that have come from Latin or French are usually written with -ible, but those formed in modern English from current verbs are written with -able:

admissible     combustible     compatible     intelligible     perceptible     plausible    

advisable     changeable     comparable     desirable     forgettable     understandable

When in doubt, check a dictionary for whether -ible or -able is preferred. Words that do not appear in the dictionary – because they are relatively new or ad hoc – can be spelled with -able:

arguable     doable     findable     playable     revisable     ungettable

See also -able/-eable.

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-ic/-ical; -istic/-istical

Some adjectives formed with either -ic or -ical endings have exactly the same meaning in general use:

botanic/botanical     electric/electrical     mythic/mythical     zoologic/zoological

But in other cases the meaning is different, and you will need to check to make sure you are using the correct form:

an astronomic rise in prices [a large increase]     astronomical calculations [calculations made in astronomy]

comic [relating to comedy]     comical [amusing]

economic issues [relating to the economy]     economical with the housekeeping [keeping costs down]

a historic building [important because of its history]     historical data [in the past]

Check formal names (such as those of gardens, zoos, societies and precincts) that contain interchangeable forms:

Australian National Botanic Gardens     Royal Tasmanian Botanical Gardens

The -ly adverbs derived from these adjectives are always based on those with the -ical ending, whatever the meaning:

astronomically     botanically     economically     historically

The same alternatives occur with -istic and -istical:

statistic/statistical/statistically     mechanistic/mechanistical/mechanistically
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The names of many academic disciplines end in -ics (eg mathematics, classics, economics, physics, statistics, ethics). A few terms end in -ic (eg logic, rhetoric). In either case, such terms are treated as a singular collective noun:

Mathematics is hard work.

Logic is a mystery to me.

Politics is never balanced.

But when a term ending in -ics is made specific, preceded by a determiner (eg the, their) or adjective, it takes on a plural meaning:

The economics of climate change are complex.

Our current politics are very shallow.

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These suffixes mean and sound the same, but the -ify ending is much more common; -efy occurs in only 4 words:

amplify     beautify     fortify     gratify     magnify     notify     purify     quantify

liquefy     putrefy     rarefy     stupefy

[The Macquarie dictionary gives liquify as an alternative to liquefy.]

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-ise/-ize; -yse/-yze

Use -ise or -yse verb suffixes rather than -ize or -yze:

analyse     civilise     crystallise     fertilise     italicise     organise     paralyse

This includes the use of -isation in abstract nouns formed from -ise verbs:

civilisation     crystallisation     fertilisation     italicisation     organisation

Exceptions to this spelling rule in Australia are for proper names of some international organisations and programs (eg World Health Organization) or when quoting original material.

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Many nouns describing occupations can be formed by adding -ist to either a noun or the related adjective (eg agricultural), with no difference in meaning:

agriculturist/agriculturalist     horticulturist/horticulturalist

In Australian English, the longer forms have traditionally been used. This may be changing, because the Macquarie dictionary gives preference to horticulturist.

Caution! Sometimes there is a difference in meaning. A naturalist studies nature. A naturist is a nudist.
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-ment for verbs ending with -dge

Verbs ending in -dge can be spelled with or without the e:

abridgment/abridgement     acknowledgment/acknowledgement     judgment/judgement     lodgment/lodgement

However, all English-speaking countries use judgment, without the e, in legal contexts.

Be consistent in retaining or dropping the e if more than 1 of these words is in your document.

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Australians mostly use the -ogue ending rather than the -og ending:

catalogue     epilogue     homologue     monologue     travelogue

Exception are analogue/analog and dialogue/dialog, which are used with different meanings in different contexts: analog in electronics, and analogue in literary and philosophical writing; dialogue for a conversation, and dialog in relation to computer software.

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-os/-oes for plural nouns

For words ending in -o, some plurals are spelled with -oes, and some with -os. A few words are consistently spelled one way or the other:

echoes     heroes     potatoes     tomatoes

avocados     impresarios     mementos     pianos     stilettos     sopranos     tamarillos

Check your dictionary for spelling, and make your text consistent.

Caution! Use only 1 dictionary while you work on a document – preferably a comprehensive, unabridged edition. Dictionaries may vary in the spelling and hyphenation of some words, even between editions. For example, the Australian Oxford English dictionary is not identical to the Macquarie dictionary, and the 6th edition of the Macquarie dictionary differs from Macquarie online.
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Use the -our ending rather than the -or ending:

arbour     armour     behaviour     colour     favour     glamour     honour     labour  

The -or spelling is often used in complex words derived from, or closely associated with, these words. However, there are exceptions:

arborist     glamorous     honorary     laborious
armoury     colouration     favourable

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Program is the preferred spelling in the Macquarie dictionary for all uses of the word in Australia.

Did you know? Historically, British usage has distinguished between program for computer programs, and programme for all other uses. In the past, programme has been used in Australia in accordance with this tradition, and is still seen in some older titles.

However, the Oxford English dictionary has now endorsed program because it is a much earlier spelling than programme, and analogous with histogram, telegram and many other terms.

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In Australia, the -re ending is almost always used where the spelling option with -er exists:

calibre     centre     fibre     lustre     spectre

But the -re/-er endings mark an important difference in Australian English between metre (unit of distance) and meter (measuring instrument). Compound terms that refer to types of measuring instrument are always spelled with -er:

gasometer     odometer     pedometer     speedometer     spectrometer     thermometer
Reminder. ‘Metre’ is a unit of distance; ‘meter’ is a measuring instrument. 
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In Australian English, some words end with -se when they are verbs and -ce when they are nouns:

He was licensed [verb] to take passengers.

They did not have a licence [noun].

She practised [verb] her bandaging skills.

He opened a second physiotherapy practice [noun].

Some pairs like this have different pronunciations: as z with -se and s with -ce:

advise [verb]     advice [noun]    

devise [verb]     device [noun]

Although the -ce spelling is used with certain nouns in Australian English, the -s spelling is still used in words derived from them:

offence/offensive     defence/defensive     pretence/pretension
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Nouns ending in -us often come from Latin and are common in science. The adjectives related to them are formed by adding the English -ous ending – which sounds the same but is spelled differently:

fungus/fungous     humus/humous     mucus/mucous     oestrus/oestrous     phosphorus/phosphorous

See Spelling in chemistry for further information about the correct usage for phosphorus and phosphorous.

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