blunder .. a gaff is a hook

bird names are lower case

also Nielsen poll

current usage is jail, not gaol

If you mean a kind of attic then it's garret. The federal environment and arts minister, ex Midnight Oil, is Peter Garrett.

to gauge someone's interest ... not *guage

gay and lesbian people or couples—not 'gays and lesbians'

has a very specific meaning and is used in art, music and literature to indicate a style or type. Poetry and drama are genres within literature. Jazz is a genre within music. Major branches of knowledge such as science, history, philosophy or religion cannot sensibly be described as genres.

party drug

gold leaf, gold paint ... but you feel guilty

one word

gone missing, dead

for goodness sake (no apostrophe)

complicated problem to be cut through

the ape, guerilla the war

Australian government, federal government, state government, the government, Howard government, Rudd government ... Commonwealth government

not grafitti

as in 'her granny'

refers to England, Scotland and Wales. UK (United Kingdom) refers to England, Scotland, Wales and Northern Ireland.

grill is for cooking, grille is a grating

events can be either groundbreaking (innovative) or historic (historically significant), never 'ground making'

is a feeling; gilt involves gold paint or gold leaf