I always comes before E (but after C, E comes before I) In most words like friend, field, piece,pierce, mischief, thief, tier, it is "i" which comes before "e". But on some words with c just before the pair of e and i, like receive, perceive, "e" comes before "i". But this is not always obeyed as in case of weird and weigh,weight,height,neighbor etc.

 Mnemonic:
I before E, except after C\nOr when sounded "A" as in neighbor, weigh and weight\nOr when sounded like "eye" as in height\nAnd "weird" is just weird

 Mnemonic:
When it says ee, Put i before e, But not after c