Linking

a beauty
a castle
a day
a joke
a hand
a king
a loom
a minister
a night
a queen
a room
a theater
a weaver

/w^n/
a one-time offer

/yuw/
a ukelele
a unicorn
a uniform
a university

h is pronounced
a happy person
a hungry dog
a hint

an apple =  a napple
an emperor = a nemperor
an imagination
an old minister
an owner
an umbrella
an understatement

silent h
an honest person
an honor
an hour