Basic Spelling Rules – The “ie and ei” Rule
The “ie and ei” Rule. Use i before e except when the two letters follow c and have a long e sound or when the two vowels are pronounced long a.
long e after c: conceit, deceive, ceiling
long a: vein, weight, veil, neighbor
other letters: shield, believe, grieve, mischievous
Exceptions: weird, foreign, forfeit, sleight, ancient, height, surfiet, sovereign.