The nuns were WRONG.
If a person allows the Host to dissolve completely in the mouth, and never actually swallows any part of the host, he does not receive the sacrament.
This happens much more rarely nowadays, for three reasons:
1) the hosts themselves are more substantial, and do not dissolve so quickly without chewing and swallowing;
2) People are no longer mistakenly instructed not to chew the host;
3) Many people receive under both species.
Thanks for showing yet another change in teaching from the unchanging teaching of the Roman Catholic Church.
Pinging a bunch of former Catholics for them to find out that for their entire lives, they had been lied to about how to take communion and that they never really received the sacrament.
Now, that (not actually properly receiving the eucharist) according to Catholic doctrine would then probably put untold millions of Catholics for generations in hell.
And the RCC's answer for that is....... what?
Do Do That Voodoo That You Do So Well