Here's a breakdown:
The Rule
The rule generally applies when the combination of "ie" or "ei" makes a long "e" sound.
* Examples:
* believe
* achieve
* piece
* field
* niece
Exceptions
There are many exceptions to this rule, including:
* Words with a "c" sound:
* ceiling
* receipt
* conceit
* science
* Words with a "sh" sound:
* shepherd
* ancient
* Words where the "i" and "e" follow a "w" or "u":
* weird
* weight
* their
* seize
* Words with an "ei" combination that makes a long "a" sound:
* neighbor
* weigh
* eight
* freight
Common Exceptions
* "friend"
* "foreign"
* "height"
* "weird"
* "their"
* "leisure"
Remember
The rule is a useful tool, but it's not infallible. The best way to learn the correct spelling is to memorize the exceptions or look them up in a dictionary.