the -ti- in -titlan in placenames

[Frances Karttunen]

> Now I'm still working with place names in the various manuscripts, and to
> me it's still a puzzle the difference between "Popocatepetl" and
> "Popocatepec."

Tepe:-tl is the word for 'hill, mountain'

The stem is tepe:-

Tepe:-c is the stem with the locative suffix -c/-co.  (The form -co is added
to stems that end in consonants, and the form -c is added to stems that end
in vowels.)

So tepe:c is that locative of tepe:tl.

The difference is between the hill itself and the location.

Fran