re + act --> react
inter + act --> interact
red + act --> redact
<red-> is a pre-vocalic allomorph of <re->
act + u + al --> actual
ang + (e)r + ed --> angered
ang + (e)r + ing --> angering
ang + (e)r + y --> angry
hung(e)r + y --> hungry
ang + ina --> angina
ang + st --> angst
angu + ish --> anguish
<gu> digraph toggles with <g> to preserve phonological governance
anx + i + ous --> anxious
amb/ + ig + u + ous --> ambiguous
augur + s --> augurs
augur + ed --> augured
augur + ing --> augur + ing
augur + y --> augury
augur + y/i + es --> auguries
in + augur + al --> inaugural
in + augur + ate --> inaugurate
in + augur + ate/ + ion --> inauguration
aut + o + bi + o + graph + y --> autobiography
aut + o + mobile --> automobile
aut + ism --> autism