[tex-hyphen] wrong hyphenation of friendly?

[Karl Berry]

Hi Pablo,

    I have noticed that TeX doesn't hyphenate friendly, although
    http://www.merriam-webster.com/dictionary/friendly shows it as
    friend-ly. 

In American English, \righthyphenmin=3, hence no hyphenation.  
I can't make out from that web page whether it is showing hyphenation or
syllabification.

    it seems that hyphenation rules are different from
    syllabification. 

It's basically syllabic, but it's true there is no perfect correspondence.

    It also seems that hyphenation rules aren't even
    related to word pronunciation 

Well, it's all "related", but in an imprecise rather than algorithmic
way, as far as I know.

    (if I don't get it wrong,
    http://www.merriam-webster.com/dictionary/record hyphenates in three
    different forms as verb, noun or adjective).

Yes.  ("Record" is an example in the TeXbook, too.)  The verb form is
pronounced differently than the others, BTW.

    is there a rule to the rules? 

I've never seen anything like a set of rules for US English hyphenation
rules that covers everything.

    it strikes me that a word such as Apollodorus isn't hyphenated
    Apol-lo-do-rus

I'm not sure about Apollo and derivatives.  Apol-lo does seem weird, but
not completely implausible.  The hyphenation after lo- (that TeX misses)
seems like it would be ok ... but then, hyphenation of loan words like
that can be different than similar "native" words.

   [last hyphen is my guess].)

I don't know the word, but from the way it looks I would think ...dor-us,
which is again forbidden by \righthyphenmin=3.


Further reading :) --
There is a long list of exceptions and accompanying article at
http://ctan.org/pkg/hyphenex

Gerard Kuiken developed a much larger set of hyphenation patterns:
http://ctan.org/pkg/ushyph
(It's installed in TeX Live.)

Best,
Karl