Base word
or
Root word
or
Root word
Am, Amor
Love, liking
Amiable, amorous
-s, -es
Plural, more than one
Books, Sandwiches
pre-
before
preview
Aud
hear, listen
Audio, auditorium
-ed
past tense (regular verb)
Called, learned
un-
not
Unhappy
bio
life
Biography, Biology
-less
without
Careless, hopeless
re-
back, again
reread, replay
cycl
wheel, circular
Bicycle
-er
one who, a person who
Baker, teacher
Not
Nonsense
geo
earth
Geography, geology
-ful
full of
Hopeful, careful
sub
under
submarine