I came across a long paper with many cognates of PIE roots, some examples:
where *-s- is an interformant in both examples.
Due to my lack of knowledge of judging or proving PIE cognates, I would like to find out whether these cognates are true or not.
Basically, extensions are… no one knows what exactly they are or whether they really exist. They look like suffixes, because they are encountered at the final position of what one thinks is the Proto-Indo-European root. The problem with them – I mean the extensions (élargissements, Erweiterungen etc.) – is that it is impossible to define their functions or meanings. Some clever blokes try to speculate that they modify slightly the meaning of the root and therefore may be called determinatives. Benvenist went as far as trying to explain them as ordinary suffixes, but this attempt of his failed, like his root theory, too. There is another major problem to that. Some roots, or what linguists believe to be such, are nowhere detected without extensions, like, for instance, *gen-, allegedly meaning ‘to pinch’ – look it up in IEW. This makes us question the correctness of the reconstruction *gen-.
The idea is not whether PIE had preformants and interformants, but that the preformants are in fact suffixes and "extensions".
argument is not correct if not impossible, such word forming was never in proto-indo-european not even earlier, and proto-indo-european was a suffixional language, didn't have 'preformants" "interformants ", and only had s- mobile as kind of prefix, hence this argument is not tenable. indo-european verbs existed as the main root and some kind of very old determinative postpositional consonantal extensions which may have been in pre-proto-indo-european with a particular meaning.
