The hexagraph ⟨oidhea⟩, for example, represents the same sound (approximately the vowel in English "write") as the trigraph adh, and with the same effect on neighboring consonants.
⟨eabhai⟩ is used to write /əu̯/ (/oː/ in Ulster), e.g. breabhaid "sortie", deabhaidh "haste, skirmish", feabhais "improvement" (gen), leabhair "books", meabhair "minds".
⟨eamhai⟩ is used to write /əu̯/, e.g. creamhaigh "garlic" (gen), sceamhaim "I bark", seamhain "semiology", sleamhain "slippery", teamhair "tor, hill".
⟨eidhea⟩ and ⟨eighea⟩ are both used to write /əi̯/ (/eː/ in Ulster), e.g. eidheann "ivy", feidheartha "penniless", leigheas "healing", deideigheanna "soft toys", deighealfaidh "will divide".
⟨oidhea⟩ and ⟨oighea⟩ are both used to write /əi̯/, e.g. oidheanna "fates", sroigheall "scourge", broigheall "cormorant", oigheann "oven", oighear "ice", poigheachán "(snail)shell".