As adjectives the difference between allied and helpful
is that allied is relating to the allies (allied nations during world war one) while helpful is furnishing help; giving aid; useful.
allied
English
Verb
(head)
(ally)
helpful
English
Alternative forms
* helpfull (archaic)
Adjective
(
en adjective)
Furnishing help; giving aid; useful.
See also
* helpfully
* helpfulness