I'm so confused about the "intensive particle" in Proto-Indo-European (PIE) right now. The exact nature of the particle is related to my previous ponderings on uvulars and their Pre-IE origins. It seems that some Indoeuropeanists reconstruct *ǵe and some reconstruct *ge. Then there's also *gʰe which appears to be reconstructed alongside *ǵʰi as in the emphatic negation *né-ǵʰi "not at all". All of them are supposedly "intensive" particles with the same function.
What makes this more confusing is that I'm pretty sure that the pronoun *h₁éǵoh₂ "I" has to be the product of *e, *ǵe [intensive particle] and *-oh₂ [old 1ps subjunctive]. Yet if so, everything in that word implies that the velar was originally *ǵ, not *g (see Paleoglot, The Origin of Indo-European Ego, Apr 07 2008). Yet if it started out as *ǵ, it can't explain what appears to be an intensive or punctual suffix *-g- used on verbs like *yeu-g- "to join" (c.f. *yeu- "to join") and *bʰoh₁-g- "to bake" (c.f. *bʰeh₁- "to warm"). Surely this is connected, no? It also seems suspect that a productive particle or suffix would have used such a marked phoneme (i.e. As I've stated earlier, *g is likely to me to be a uvular, creaky-voiced stop rather than a "plain" one as per traditional reconstruction). My instinct is telling me that it surely must have once been *ǵ (i.e. a plain voiced velar stop in the revised reconstruction) but then this denies a link to the verbal extension in uvular *-g-.
I'm so confused and so far I can't make heads or tails of it yet I know that all of these things must be connected somehow.
(November 13 2008) Corrected the definition of *bʰeh₁- from "to burn" to "to warm". It's just a slight technicality that doesn't affect my above reasoning.
 Beekes, Comparative Indo-European Linguistics (1995), p.222 (see link).
 Both unpalatalized *gʰe and palatalized *né-ǵʰi with different voiced velars are shown boldly on the same page of Mallory/Adams, The Oxford Introduction to Proto-Indo-European and the Proto-Indo-European World (2006), p.69 (see link), emphasizing my point that something may be a little wonky with the reconstruction of this particle which appears to have too many possible forms: *ǵe, *ge, *ǵʰe, *gʰe, *ǵʰi or *gʰo.