Since this is a contrast that can only occur initially, the spelling of /g/ is always <g> while the /h/ sound is spelled <h>.
This is a contrast between a voiced stop and a voiceless fricative. both in the velar or glottal area of the mouth. It may cause some problems to learners accustomed to strongly fricative /h/ sounds.
Interesting pairs include:
The figure for the mean density is 3.1%. The set makes 80 semantic contrasts, a loading of 54%.
gad had Gael hail Gaels hails Gael hale gale hail gales hails gale hale gag hag gags hags gaggle haggle gaggles haggles gait hate gaits hates gal Hal gall hall galls halls gall haul galled hauled galls hauls galling hauling galley Halle gallows hallows gamma hammer gammas hammers gang hang ganging hanging gangs hangs ganged hanged ganger hangar gangers hangars gap hap gaps haps garden harden gardened hardened gardening hardening gardens hardens Gary Harry gash hash gasp hasp gasps hasps gate hate gated hated gating hating gates hates gat hat gaud hawed Gaul hall Gauls halls Gaul haul Gauls hauls gaunt haunt gauze haws gawk hawk gawks hawks gay hay gayness heinous gays haze gaze haze gazed hazed gazes hazes gazing hazing gear hear gearing hearing gears hears geld held gharries harries ghee he ghost host ghosted hosted ghosting hosting ghosts hosts gillie hilly gilt hilt gird heard gird herd girded herded girding herding girds herds girdle hurdle girdled hurdled girdles hurdles girdling hurdling girl hurl girls hurls go ho go hoe goes hoes going hoeing goad hoed goal hole goals holes goal whole goals wholes goalie holy goalies holies goalie wholly gob hob gobs hobs gobble hobble gobbled hobbled gobbles hobbles god hod gods hods gold hold gold holed golly holly gone Hon goo Hoo goo who good hood goods hoods gooey hooey goof hoof goofs hoofs Goole who'll gore hoar gorse hoarse gory hoary gorier hoarier goriest hoariest got hot gowned hound guard hard guardship hardship guardships hardships guide hide guides hides guiding hiding guise hies gull hull gulled hulled gulling hulling gulls hulls gum hum gummed hummed gumming humming gums hums gun Hun guns Huns gunny honey gush hush gushes hushes gushing hushing gushed hushed gut hut gutted hutted guy hi guying hieing guys hies
John Higgins, Shaftesbury, October 2010.