One rule we learn at school is the memory trick, “i before e except after c.”

i before e – believe field, believe, niece, piece
except after c so ei – receive, receipt, ceiling,

Do we always use ei after c? Unfortunately, no.
Look at these words with ie or ei after the c. Read them aloud.

ancient, efficient, science, society, seize, receipt, receive, deceive, ceiling.

Do you notice that the -cei- words have different sounds?

These words have a “sh” sound: ancient, efficient

And these have a “s” sound: science, society, seize

receipt, receive, deceive, ceiling have a long vowel “ee” sound

So we need to change the spelling rule to
– “i before e except after c if it has a long “ee” sound” or “i before e so long as the word rhymes with bee.”