One thing I have noticed in learning Latin is that a lot of the so-called irregularities are sound changes.
For example: (stem ends in g + ending begins with s yields x)
For short, I write: g + s → x
another one is: g + t → ct
I have three questions:
Thanks in advance.
Sorry, don’t agree: do a Google search on afui and afuturus and they pop up all over the place.
I was careful to say that it had only occurred that way when I have seen it thus far 
This entry, http://lysy2.archives.nd.edu/cgi-bin/words.exe?afui , shows some alternatives for the regular absum, abesse, abfui, abfuturus.
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I was careful to say that it had only occurred that way when I have seen it thus far
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The only way to be right all the time is to make sure that you can never be wrong! 
Thank you for your replies. Part of the problem with a literary language like Latin is that you can’t ask a native speaker!
Hey,
you noticed the sound-changes very well. There are entire books about it. You can also see the changes from old-Latin to Classical Latin and Medieval Latin. Most of the sound changes you can check in a historical grammar, like Niederman, Phonétique historique du Latin. Or in English: Palmer, The Latin language. The first is an entire book about it.
If you only want to see the changes in classical Latin, you can also find them sometimes in regular grammars.
With ‘abesse’ you have absum, afui, (afuturus)
‘adesse’ you have adsum, sometimes assum, adfui and sometimes affui.
Obesse = obsum, obfui
In Rome with most words you had two manners of orthographe; a conservative and a progressive. The conservative was the etymological one and in the progressive way they wrote nearly like they spoke.
There was always one orthography the most cummon one.
Besides obtineo, sometimes we also find optineo, cause that was how they pronounced it!
If you really want to be sure, you can always see in a dictionnary or in one of the books mentioned above.
Greetz,
Moerus.
Just for your own reference, an “X” can be formed by the following combinations:
G+S i.e.- rex, reg-
C+S i.e.- dux, duc-
H+S i.e.- traho, traxi
V (consonant)+S i.e.- vivo, vixi
And as for G+T becoming C+T, that is just basic consonant weakening which is found in all Indo-European languages:
B weakens to P
G weakens to C/K
V (modern V) weakens to F
ZH weakens to SH
J (modern J) weakens to CH
TH (English) becomes TH
Z (English) becomes S
Consonants are most often weakened before a T or an S. Try to say one of the harder consonants (the ones on the left side) before a T or an S qucikly and you will see why we weaken it.
As your article explains.
Wow, I’m sorry for my first response… I don’t know what I was thinking! :
My purpose in bringing this up was selfish. By having a list of sound changes and knowing what and when to expect them to occur, I would then have fewer so-called irregularities to remember when dealing with parts of verbs and declensions of nouns.
Example, if I know that: t+s->s, then I can remember pont as the stem and use an ending of s in the nominative to get pons. This means one less irregularity.
Another example, if I remember a prefix of prod- and a stem of sum and note that: d+s->s to get prosum and with a stem of futurus and note that: d+f->f to get profuturus and then when the stem is -est, I get prodest since d+vowel->d+vowel.
With prosum, it’s probably easier to remember that pro has no d before a vowel (or has d before a consonant). Similar with posse: pos before an s, pot before a vowel (pos-sum, pot-es)
If you try to make a rule d+s → s, or d+f → f, you could get into trouble with other words (adesse would have afui (= ab-fui) instead of affui; obesse would have ofui etc.). See also Moerus’s post (who’s far more learned than I am, I just worked through the compounds of esse recently )
Ingrid
Ingrid: I’ve never seen affui but have seen afui. Some of these changes are fairly constant others are not. The tutorial on Perfect Stems has gone a long way in helpiing me.
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Ingrid: I’ve never seen affui but have seen afui. Some of these changes are fairly constant others are not. The tutorial on Perfect Stems has gone a long way in helpiing me.
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according to my grammar, affui can be used instead of adfui, but my exercise book uses adfui only. It does use afui consistently for abfui though.
Ingrid
the principle parts of absent are absum abesse afui afuturus and for present it is adsum adesse adfui adfuturus.