Heirs is sounded as 'a'! Phonetically it would make no sense if it were spelled Hiers and pronounced 'airs'. The rule only applies to words where there could be some confusion of spelling due to the pronunciation; science, for example, is not an important word for discussing this rule, and neither is vein (well it sounds as A at least).
Seize is a real exception, as is Weird. In both cases they can be confusingly flipped around and still seem to make some phonetic sense: Sieze and Wierd.
Last edited by Clopin; 09-11-2015 at 11:50 PM.
So with the courage of a clown, or a cur, or a kite jerkin tight at it's tether
You would expect weird to be an exception.