Doublets
fragile
frail
Fragile is Latin.
Frail is French.
egg
Double.
graph
<ph> ~ /f/
home
The replaceable <e> marks the vowel sound.
catch
capture
Catch is French.
Capture is Latin.
misspoke
No double.
chrome
<ch> ~ /k/
ski
No complete English word ends in <i>, so this must be borrowed.
reason
ratio
Reason is French.
Ratio is Latin.
robber
Double.
gym
<y> in the middle
flu
No complete English word ends in <u> so this must be a clip (of influenza).
potion
poison
Potion is Latin.
Poison is French.
attract
No double.
microscope
Connecting vowel <o>.
is, as, his, us, has
Content words cannot end with a single <s>, so these must be function words.
tradition
treason
Tradition is Latin.
Treason is French.
questionnaire
Double.
synchronize
<y> in the middle AND <ch>~/k/
tomato
English content words don't end in <o>, so this must be a loan word.