There is a discussion in TosafosTosafos as to the identity of R. Achai. Rashbam claims that this is R. Achai Gaon, the author of the SheiltosSheiltos, and because he lived after all the amoraimamoraim he always has a different lashonword associated with him such as פריך רב אחאי or פשיט רב אחאי.
Rabbeinu TamRabbeinu Tam rejects the view of Rashbam, and offers a different reason for the unique lashon ofwords associated with R. Achai. TosafosHe asserts that every amora had their own unique lashonwords so the fact that R. Achai also had a unique lashon unique words does not indicate that he was not a regular amora. Rabbeinu Tam provides three examples of leshonoswords unique to specific amoraim 1) מגדף בה ר' אבהו (3 תהי בה ר' יוחנן (2 לייט עלה אביי.
The question is: is all this talk about unique leshonoswords actually true?
There are in fact 9 places in the Talmud where a steppoint is introduced with פריך and in all 9 cases the person doing the פריך is R. Achai/Acha. (Yevamos 24a, Yevamos 46a, Kesubos 47a, Kiddushin 13a, Shavuos 41b, Zevachim 102b, Chullin 65b, Bechoros 6a, Niddah 33a.)
While תהי בה is indeed used for R. Yochanan more often than for other amoraim (Kesubos 107b, Kiddushin 55b, Bava Kamma 112b, Bava Basra 39a, Bechoros 42b,) it is still used for a whole bunch of amoraim, such as R. Zera (Berachos 38b), Reish Lakish (Zevachim 13b), R. Elazar (Eruvin 66a, Bava Kamma 76b), such that it is a bit of a stretch to call it R. Yochanan's unique lashon. In fact, in the parallel passage in Tosafos HaRoshTosafos HaRosh one of the examples given of a unique lashonwords is תהי בה ר' זירא!
While it is possible that Rabbeinu Tam meant not that these leshonoswords were unique to these amoraim, but that these amoraim always used these leshonoswords, it would still be a stretch because each of these amoraim only use their specific lashonwords a few times in the entire Talmud (aside from פריך רב אחאי/אחא which is used 9 times).
Furthermore, the lashon ofphrasing employed by Rabbeinu Tam וכל אמורא היה תופס לשונו implies that each amora chose his unique word. However, the unique words in question are all verbs describing actions taken by the amoraim. Therefore the amoraim were not using these words themselves; rather, the redactors of the Talmud chose to use certain words to describe the actions of certain amoraim.