It is really easy to understand the difference between aid and aide. We pronounce them the same way and their meanings are very close.
Aid can be used as a verb, adjective and a noun. It’s synonyms are: to help, to assist, help and assistance. For example:
Republicans want to keep the bill focused on increasing small-business aid.
Dating app grants aid to small businesses faster than Uncle Sam.
Efforts to aid those experiencing homelessness must persist after COVID-19 pandemic.
Aide can be used only as a noun and its meaning is assistant. For example:
At least one other close aide to the governor was also tested for the virus.
A top aide to D.C. Mayor Muriel Bowser has died from the coronavirus.