'e' could go to 'ie' or 'i'

'e' could go to 'ie' or 'i'

injerir - to introduce, to insert
advertir - to notice, to warn
consentir - to allow, to permit
desmentir - to deny
diferir - to postpone, to put off
digerir - to digest, to assimilate
disentir - to disagree
divertir - to entertain, to amuse
hervir - to boil
ingerir - to consume, to ingest
interferir - to jam, to interfer
invertir - to reverse, to invert
malherir - to injure seriously
mentir - to lie
preferir - to prefer
referir - to tell, recount