Most students of English are familiar with the "i before e, except after c" mnemonic rule of thumb. If one is unsure whether a word is spelled with the sequence ei or ie, the rhyme suggests that the correct order is ie unless the preceding letter is c, in which case it is ei. For example:
ie in believe, fierce, collie, die, friend
ei after c in deceive, ceiling, receipt, ceilidh
Edward Carney calls it "this supreme, and for many people solitary, spelling rule". However, the short form quoted above (without qualifications concerning pronounciation) has many common exceptions; for example:
ie after c: species, science, sufficient
ei not preceded by c: seize, weird, vein, their, foreign, feisty
For some reason there is only one exception that I have trouble with - 'weird', an adjective meaning strikingly odd or unusual, especially in an unsettling way; strange.
So here is a tip to help you remember how to spell it. 'We are weird' - we is the beginning of weird. Or perhaps all you need to know is that weird is a weird word!