Rules of English

This has been on my mind for a while. I just decided to look into it for myself.
Just in case you were wondering, this bunk about “i before e except after c” is useless. Even admitting the “except when sounding like ‘a'” rule (beige), there are plenty of exceptions. “Height” for example. So lets add this one, “except when followed by ‘gh’.” That’s pretty solid, there are no words in my dictionary file with the series of letters iegh. (Many of these ‘eigh’ words also fall under the ‘a sound’ exception, ie weight, eight.) Actually, this leaves a lot of exceptions that can be better dealt with.

• conterfeit
• feisty
• forfeit
• heifer
• their
• veil
• weird

This can all be covered if we accept that this rule only applies when words have the ‘ee’ or long e sound. (Which really limits its usefulness. But hey, let’s get somewhere.)
Of course, we also have to excuse foreign words. We also have to excuse any word where there’s a syllable break between the two letters. You’ll have to figure those out yourself. (deity, science)
Now let’s see where we are: “When having the long e sound, i before e except after c, before gh, part of a foreign word, or when spanning syllables.” Ouch. Okay, I can only get the core of that into a grep expression, so I have to sort out the pronunciation and origin exceptions myself.
grep [^c]ei[^{gh}] words.txt | more
Here’s a sampling of what’s left

• caffeine
• protein
• seize

Then on the other side, the rule still doesn’t say anything about the words included in the list above or those with a c, such as these.

• ancient
• conscience
• deceit
• efficient
• glacier
• species

And I’m not seeing a pattern there at all.